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1,711 results on '"Department of Geology and Geophysics"'

1. Raised Coral Terraces at Malakula, Vanuatu, Southwest Pacific, Indicate High Sea Level During Marine Isotope Stage 3

Author: Cabioch, Guy and Ayliffe, Linda K
Published: 2001
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2. Quantifying magmatic, crustal, and atmospheric helium contributions to volcanic aquifers using all stable noble gases: Implications for magmatism and groundwater flow

Author: Now at Department of Geology and Geophysics, University of Minnesota, 310 Pillsbury Drive, S. E., Minneapolis, Minnesota 55455, USA., Saar, M. O., Castro, M. C., Hall, C. M., Manga, M., Rose, T. P., Now at Department of Geology and Geophysics, University of Minnesota, 310 Pillsbury Drive, S. E., Minneapolis, Minnesota 55455, USA., Saar, M. O., Castro, M. C., Hall, C. M., Manga, M., and Rose, T. P.
Published: 2013

3. Indirect crustal contamination: evidence from isotopic and chemical disequilibria in minerals from alkali basalts and nephelinites from northern Tanzania

Author: Department of Geological Sciences, The University of Michigan, Ann Arbor, MI 48109-1063, USA, US, Physical Science Division, Rock Valley College, Rockford, IL 61114, USA, US, Department of Geology and Geophysics, University of Edinburgh, Edinburgh, EH9 3JW, UK, GB, Ann Arbor, Paslick, Cassi R., Dawson, J.B., Lange, Rebecca A., Halliday, Alex N., James, D., Department of Geological Sciences, The University of Michigan, Ann Arbor, MI 48109-1063, USA, US, Physical Science Division, Rock Valley College, Rockford, IL 61114, USA, US, Department of Geology and Geophysics, University of Edinburgh, Edinburgh, EH9 3JW, UK, GB, Ann Arbor, Paslick, Cassi R., Dawson, J.B., Lange, Rebecca A., Halliday, Alex N., and James, D.
Abstract: ???Alkali basalts and nephelinites from the volcanic province of northern Tanzania contain pyroxene and nepheline that show evidence for chemical and/or isotopic disequilibria with their host magmas. Olivine, pyroxene, nepheline and plagioclase all appear to be partially xenocrystic in origin. Five whole rock/mineral separate pairs have been analyzed for Sr, Nd, and Pb isotopic compositions. The 206 Pb/ 204 Pb ratios are distinct by as much as 20.94 (whole rock) vs. 19.10 (clinopyroxene separate). The Sr and Nd isotopic disequilibria vary from insignificant in the case of nepheline, to?? 87 Sr/ 86 Sr of 0.0002 and???? Nd of 0.7 in the case of clinopyroxene. The mineral chemistry of 25 samples indicates the ubiquitous presence of minerals that did not crystallize from a liquid represented by the host rock. The northern Tanzanian magmas are peralkaline and exhibit none of the xenocrystic phases expected from crustal assimilation. The disequilibria cannot be the result of mantle source variations. Rather the xenocrystic phases present appear to have been derived from earlier alkali basaltic rocks or magmas that were contaminated by the crust. Material from this earlier magma was then mixed with batches of magma that subsequently erupted on the surface. Disequilibrium in volcanic rocks has potentially serious consequences for the use of whole rock data to identify source reservoirs. However, mass balance calculations reveal that the 206 Pb/ 204 Pb isotopic compositions of the erupted lavas were changed by less than 0.25% as a result of this indirect crustal contamination.
Published: 2006

4. Heat capacity and phase equilibria of hollandite polymorph of KAlSi 3 O 8

Author: Department of Geological Sciences, University of Michigan, Ann Arbor, MI, 48109-1005, USA, Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN, 55455, USA, Fachbereich Materialwissenschaften, Universit??t Salzburg, Hellbrunnerstr. 34, 5020, Salzburg, Austria, Ann Arbor, Withers, Anthony C., Essene, Eric J., Dachs, E., Yong, Wenjun, Department of Geological Sciences, University of Michigan, Ann Arbor, MI, 48109-1005, USA, Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN, 55455, USA, Fachbereich Materialwissenschaften, Universit??t Salzburg, Hellbrunnerstr. 34, 5020, Salzburg, Austria, Ann Arbor, Withers, Anthony C., Essene, Eric J., Dachs, E., and Yong, Wenjun
Abstract: The low-temperature heat capacity (C p) of KAlSi 3 O 8 with a hollandite structure was measured over the range of 5???303??K with a physical properties measurement system. The standard entropy of KAlSi 3 O 8 hollandite is 166.2??0.2??J??mol???1??K???1, including an 18.7??J??mol???1??K???1 contribution from the configurational entropy due to disorder of Al and Si in the octahedral sites. The entropy of K 2 Si 4 O 9 with a wadeite structure (Si-wadeite) was also estimated to facilitate calculation of phase equilibria in the system K 2 O???Al 2 O 3???SiO 2 . The calculated phase equilibria obtained using Perple_x are in general agreement with experimental studies. Calculated phase relations in the system K 2 O???Al 2 O 3???SiO 2 confirm a substantial stability field for kyanite???stishovite/coesite???Si-wadeite intervening between KAlSi 3 O 8 hollandite and sanidine. The upper stability of kyanite is bounded by the reaction kyanite (Al 2 SiO 5)??=??corundum (Al 2 O 3)?? +??stishovite (SiO 2), which is located at 13???14??GPa for 1,100???1,400??K. The entropy and enthalpy of formation for K-cymrite (KAlSi 3 O 8??H 2 O) were modified to better fit global best-fit compilations of thermodynamic data and experimental studies. Thermodynamic calculations were undertaken on the reaction of K-cymrite to KAlSi 3 O 8 hollandite??+?? H 2 O, which is located at 8.3???10.0??GPa for the temperature range 800???1,600??K, well inside the stability field of stishovite. The reaction of muscovite to KAlSi 3 O 8 hollandite??+??corundum??+??H 2 O is placed at 10.0???10.6??GPa for the temperature range 900???1,500??K, in reasonable agreement with some but not all experiments on this reaction.
Published: 2006

5. Arsenic resistance in the archaeon 'Ferroplasma acidarmanus' new insights into the structure and evolution of the ars genes.

Author: Department of Geological Sciences, The University of Michigan, Ann Arbor, Michigan, USA, School of Biological Sciences, University of East Anglia, Norwich, UK, Department of Geology and Geophysics, The University of Wisconsin Madison, Madison, Wisconsin, USA, Ann Arbor, Banfield, Jillian F., Gihring, Thomas M., Peters, Stephen C., Bond, Philip L., Department of Geological Sciences, The University of Michigan, Ann Arbor, Michigan, USA, School of Biological Sciences, University of East Anglia, Norwich, UK, Department of Geology and Geophysics, The University of Wisconsin Madison, Madison, Wisconsin, USA, Ann Arbor, Banfield, Jillian F., Gihring, Thomas M., Peters, Stephen C., and Bond, Philip L.
Abstract: Arsenic resistance in the acidophilic iron-oxidizing archaeon " Ferroplasma acidarmanus " was investigated. F. acidarmanus is native to arsenic-rich environments, and culturing experiments confirm a high level of resistance to both arsenite and arsenate. Analyses of the complete genome revealed protein-encoding regions related to known arsenic-resistance genes. Genes encoding for ArsR (arsenite-sensitive regulator) and ArsB (arsenite-efflux pump) homologues were found located on a single operon. A gene encoding for an ArsA relative (anion-translocating ATPase) located apart from the arsRB operon was also identified. Arsenate-resistance genes encoding for proteins homologous to the arsenate reductase ArsC and the phosphate-specific transporter Pst were not found, indicating that additional unknown arsenic-resistance genes exist for arsenate tolerance. Phylogenetic analyses of ArsA-related proteins suggest separate evolutionary lines for these proteins and offer new insights into the formation of the arsA gene. The ArsB-homologous protein of F. acidarmanus had a high degree of similarity to known ArsB proteins. An evolutionary analysis of ArsB homologues across a number of species indicated a clear relationship in close agreement with 16S rRNA evolutionary lines. These results support a hypothesis of arsenic resistance developing early in the evolution of life.
Published: 2006

6. Eclogite-facies shear zones--deep crustal reflectors?

Author: Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109-1063, USA, Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071-3006, USA, Mineralogisk-Geologisk Museum, Sars Gate 1, N-Oslo 5, Norway, Fountain, David M., Boundy, Theresa M., Austrheim, Hakon, Rey, Patrice, Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109-1063, USA, Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071-3006, USA, Mineralogisk-Geologisk Museum, Sars Gate 1, N-Oslo 5, Norway, Fountain, David M., Boundy, Theresa M., Austrheim, Hakon, and Rey, Patrice
Abstract: Strongly foliated eclogite-facies rocks in 30-150 m thick shear zones of Caledonian age occur within a Grenvillian garnet granulite-facies gabbro-anorthosite terrain in the Bergen Arcs of Norway. The predominant eclogite-facies mineral assemblages in the shear zones are omphacite + garnet + zoisite + kyanite in gabbroic anorthosite and omphacite + garnet in gabbro. Eclogite-facies rocks in shear zones are generally fine-grained; alternating omphacite/garnet- and kyanite/clinozoisite-rich layers define gneissic layering. A strong shape preferred orientation of omphacite, kyanite, and white mica (phengitic muscovite and/or paragonite) define the foliation. The anorthositic eclogites show omphacite b-axis maxima approximately normal to the foliation and c-axis girdles within the foliation plane. P-wave velocities (Vp) determined at confining pressures to 600 MPa for samples from eclogite-facies shear zones range from 8.3 to 8.5 km s-1 and anisotropy ranges from 1 to 7%. The few samples with more pronounced anisotropy tend to be approximately transversely isotropic with minimum velocities for propagation directions normal to foliation and maximum velocities for propagation directions parallel to foliation. The fast propagation direction lies within the c-axis girdles (parallel to foliation) and the slow propagation direction is parallel to the b-axis concentration (normal to foliation) in samples for which omphacite crystallographic preferred orientation was determined. Vp for the granulite-facies protoliths average about 7.5 km s-1. High calculated reflection coefficients for these shear zones, 0.04-0.14, indicate that they are excellent candidates for deep crustal reflectors in portions of crust that experienced high-pressure conditions but escaped thermal reactivation.
Published: 2006

7. Isotopic variations with distance and time in the volcanic islands of the Cameroon line: evidence for a mantle plume origin

Author: Department of Geological Sciences, University of Michigan, 1006 C.C. Little Building, Ann Arbor, MI 48109-1063, USA, Department of Geology and Geophysics, University of Edinburgh, Edinburgh, EH9 3JW, UK, Department of Earth Science, University of Perugia, I-06100, Perugia, Italy, Lee, Der-Chuen, Halliday, Alex N., Fitton, J. Godfrey, Poli, Giampero, Department of Geological Sciences, University of Michigan, 1006 C.C. Little Building, Ann Arbor, MI 48109-1063, USA, Department of Geology and Geophysics, University of Edinburgh, Edinburgh, EH9 3JW, UK, Department of Earth Science, University of Perugia, I-06100, Perugia, Italy, Lee, Der-Chuen, Halliday, Alex N., Fitton, J. Godfrey, and Poli, Giampero
Abstract: The oceanic sector of the Cameroon line consists of three volcanic islands: Principe, Sao Tome and Pagalu. New 40Ar---39Ar data for Pagalu basalts, combined with published K---Ar ages for Principe and Sao Tome, indicate that all three islands have been active in the past 5 Ma. They have similar petrogenetic histories, with basements of basaltic flows capped by more evolved rocks. However, the age of the earliest exposed volcanic rocks decreases oceanward from Principe (31 Ma) to Sao Tome (13 Ma) to Pagalu (4.8 Ma). This age progression is consistent with the suggested motion of the African plate over this period of time. The average incompatible trace element compositions of 87Sr/86Sr)t increases from 0.7029 to 0.7037 and (206Pb/204Pb)t decreases from 20.2 to 18.9 from Principe through Sao Tome to Pagalu for all samples younger than 10 Ma. In addition to the overall spatial isotopic variations, Principe and Sao Tome display temporal isotopic variations, with Pb isotopic ratios becoming progressively more radiogenic. Pagalu shows no temporal geochemical or isotopic differences and the island has the least radiogenic Pb but most radiogenic Sr. These distinctive Pb, Sr and Nd isotopic compositions are also found in the early tholeiitic hyaloclastite breccia from Principe (31 Ma). Similarly, the Nd and Sr isotopic compositions are identical to those of the earliest Sao Tome lavas (13 Ma) and the Pb isotopic compositions of early Sao Tome samples are only slightly radiogenic relative to Pagalu. Therefore, it is probable that all these islands were initiated from a common source, similar to that of Pagalu, that migrated relative to the melt zone of each island with time. Since their initiation, the magma conduits at Principe and Sao Tome have been gradually modified by the introduction of a HIMU component. The common source from which the islands were initially derived probably represents ambient upper mantle, entrained with the plume head during ascent. This entrained co
Published: 2006

8. Greatlakean Substage: A replacement for Valderan Substage in the Lake Michigan basin

Author: Department of Geology and Mineralogy, University of Michigan, Ann Arbor, Michigan 48104, USA, Department of Geological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, USA, Department of Geology and Geophysics, University of Wisconsin, Madison, Wisconsin 53706, USA, Evenson, Edward B., Farrand, William R., Eschman, Donald F., Mickelson, David M., Maher, Louis J., Department of Geology and Mineralogy, University of Michigan, Ann Arbor, Michigan 48104, USA, Department of Geological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, USA, Department of Geology and Geophysics, University of Wisconsin, Madison, Wisconsin 53706, USA, Evenson, Edward B., Farrand, William R., Eschman, Donald F., Mickelson, David M., and Maher, Louis J.
Abstract: New evidence from recent field and seismic investigations in the Lake Michigan basin and in the type areas of the Valders, Two Creeks and Two Rivers deposits necessitates revision of late-glacial ice-front positions, rock- and time-stratigraphic nomenclature and climatic interpretations and deglaciation patterns for the period ca. 14,000-7,000 radiocarbon years B.P. The previously reported and long accepted pattern of deglaciation for the Lake Michigan basin started with a regular retreat from the Lake Border Morainic System, with a minor oscillation marked by the Port Huron moraine(s) and then an extensive Twocreekan deglaciation followed by a major (320 km) post-Twocreekan advance (Valders). However, we now record a major retreat between the times of the Lake Border and Port Huron moraines, followed by a gradual retreat from the Port Huron limit and interrupted by a minor standstill (deposition of Manitowoc Till), a retreat (Twocreekan) and a readvance (Two Rivers Till). No Woodfordian or younger readvance was as extensive as had been the preceding one. This sequence argues for a normal, climatically controlled, progressive deglaciation rather than one interrupted by a major post-Twocreekan (formerly Valderan) surge. This revision appears finally to harmonize the geologic evidence and the palynological record for the Great Lakes region. Our investigations show that Valders Till from which the Valderan Substage was named is late-Woodfordian in age. We propose the term "Greatlakean" as a replacement for the now misleading time-stratigraphic term "Valderan". The type section and the definition of the upper and lower boundaries of the Greatlakean Substage remain the same as those originally proposed for the Valderan Substage but the name is changed.
Published: 2006

9. Quaternary Rhyolite from the Mineral Mountains, Utah, U.S.A

Author: Evans, Jr., S. H., Nash, W. P., and University of Utah, Department of Geology and Geophysics
Subjects: geology, quaternary, geophysics, Utah, rhyolite, Mineral Mountains
Abstract: A suite of silicic volcanic rocks is associated with the Roosevelt Hot Springs geothermal area in southwestern Utah. The volcanic sequence includes Tertiary rhyolite 8 m.y. old and obsidian, ash and rhyolite of Quaternary age. The Quaternary lavas are characterized by high silica content (76.5% SiO2) and total alkalies in excess of 9 percent. Obsidians commonly contain greater amounts of flourine than water. Two older flows (0.8 m.y.) can be distinguished from younger dome and pyroclastic material (approximately 0.5 m.y.) by subtle differences in their chemistry. The mineralogy of the rhyolites consists of alkali feldspar, plagioclase, and small amounts of Fe-Ti oxides, biotite, hornblende and rare allanite. Fe-Ti oxide temperatures are 740-785 degrees Celsius for the flows and 635-665 degrees Celsius for the domes; two feldspar temperature give similar results. The phase relationships of bulk rock, glass and feldspar compositions demonstrate that the younger Quaternary rhyolites could have been derived from the earlier magma type, represented by the obsidian flows, by a process of crystal fractionation. The major phases which must fractionate are alkali feldspar, plagioclase and quartz with minor amounts of biotite, magnetite and ilmenite participating also. Trace element patterns support this scheme as well. The Tertiary lavas cannot be related to the Quaternary rhyolites and are thought to represent a separate event.
Published: 1978

10. Field study of the effects of storms on the stability and fate of dredged material in subaqueous disposal areas

Author: Bokuniewicz, Henry J. (Henry Joseph), Yale University. Department of Geology and Geophysics, Bokuniewicz, Henry J. (Henry Joseph), and Yale University. Department of Geology and Geophysics
Abstract: c - / 0 0 D HDD (TJ~U~LTJ O D D D O TECHNICAL REPORT D-77-22 FIELD STUDY OF THE EFFECTS OF STORMS ON THE STABILITY AND FATE OF DREDGED MATERIAL IN SUBAQUEOUS DISPOSAL AREAS by Henry J. Bokuniewicz, Jeffrey Gebert, Robert B. Gordon Peter Kaminsky, Carol C. Pilbeam, Matthew Reed, Catherine Tuttle Department of Geology and Geophysics Yale University New Haven, Connecticut 06520 November 1977 Final Report Approved For Public Release; Distribution Unlimited TA 7 .W34t D-77-22 1977 Prepared for Office, Chief of Engineers, U. S. Army Washington, D. C. 2 0 3 14 Under Contract No. DACW51-75-C-0008 (DMRP Work Unit No. IB08) Monitored by Environmental Effects Laboratory U. S. Army Engineer Waterways Experiment Station P. O. Box 6 3 1, Vicksburg, Miss. 39I80 L IB RA RY L-K . 4 Bureau of Reclama l'^ n v o r P ' Destroy this report when no longer needed. Do not return it to the originator. BUREAU OF RECLAMATION DEI A DEPARTMENT OF THE ARMY 92068788 WATERWAYS EXPERIMENT STATION, CORPS OF ENGINEERS P. O. BOX 631 VICKSBURG, MISSISSIPPI 39180 .IBRARY WESYV 23 November 1977 SUBJECT: Transmittal of Technical Report D-77-22 TO: All Report Recipients 1. The technical report transmitted herewith represents the results of Work Unit 1B08 of Task IB, Movements of Dredged Material, of the Corps of Engineers’ Dredged Material Research Program (DMRP). It has been a part of the Environmental Impacts and Criteria Development Project (EICDP), which has a general objective of developing techniques for determining the spatial and temporal distribution of dredged material discharged into various hydrologic regimes. The study reported on herein was part of a series of research contracts developed to achieve the EICDP general objective. 2. Regardless of the location or character of a disposal site, an integral part of the problem of assessing the environmental impact of open-water disposal operations is the ability to determine the fate of dredged material mounds subjected to storm conditions. Dredged
Published: 1977

11. Magnetic characterization of non-ideal single-domain monoclinic pyrrhotite and its demagnetization under hydrostatic pressure up to 2 GPa with implications for impact demagnetization

Author: Ravil A. Sadykov, Myriam Kars, Pierre Rochette, N. S. Bezaeva, Joshua M. Feinberg, D. M. Kuzina, Jérôme Gattacceca, Sergey N. Axenov, Dmitriy A. Chareev, Ural Federal University [Ekaterinburg] (UrFU), Kazan State University (KPFU), Faculty of Physics [MSU, Moscow], Lomonosov Moscow State University (MSU), Institute of Experimental Mineralogy, Russian Academy of Sciences [Moscow] (RAS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Center for Advanced Marine Core Research, Kochi University, Institute for Rock Magnetism, Department of Geology and Geophysics, 108 Pillsbury Hall, University of Minnesota, Minneapolis, MN 55455, USA (INSTITUTE FOR ROCK MAGNETISM, DEPARTMENT OF GEOLOGY AND GEOPHYSICS, 108 PILLSBURY HALL, UNIVERSITY OF MINNESOTA, MINNEAPOLIS, MN 55455, USA), University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Institute for Nuclear Research of Russian Academy of Sciences (INR), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), University of Minnesota [Twin Cities], and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)
Subjects: 010504 meteorology & atmospheric sciences, Physics and Astronomy (miscellaneous), Hydrostatic pressure, Analytical chemistry, Mineralogy, Pressure demagnetization, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Non-ideal single-domain monoclinic, Magnetic properties, Single domain, Pyrrhotite, Saturation (magnetic), 0105 earth and related environmental sciences, Demagnetizing field, Astronomy and Astrophysics, Thermomagnetic convection, Magnetic susceptibility, Geophysics, pyrrhotite, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Remanence, engineering, Geology
Abstract: International audience; Here we present a comprehensive magnetic characterization of synthesized non-ideal single-domain (SD) monoclinic pyrrhotite (Fe 7 S 8). The samples were in the form of a powder and a powder dispersed in epoxy. ''Non-ideal " refers to a powder fraction of predominantly SD size with a minor contribution of small pseudo-single-domain grains; such non-ideal SD pyrrhotite was found to be a remanence carrier in several types of meteorites (carbonaceous chondrites, SNC.. .), which justifies the usage of synthetic compositions as analogous to natural samples. Data were collected from 5 to 633 K and include low-field magnetic susceptibility (χ0), thermomagnetic curves, major hysteresis loops, back-field remanence demagnetization curves, first-order reversal curves (FORCs), alternating field and pressure demagnetization of saturation isothermal remanent magnetization (SIRM), low temperature data (such as zero-field-cooled and field-cooled remanence datasets together with room temperature SIRM cooling–warming cycles) as well as XRD and Mössbauer spectra. The characteristic Besnus transition is observed at $33 K. FORC diagrams indicate interacting SD grains. The application of hydrostatic pressure up to 2 GPa using nonmagnetic high-pressure cells resulted in the demagnetization of the sample by 32–38%. Repeated cycling from 1.8 GPa to atmospheric pressure and back resulted in a total remanence decrease of 44% (after 3 cycles). Pressure demagnetization experiments have important implications for meteorite paleomagnetism and suggest that some published paleointensities of meteorites with non-ideal SD monoclinic pyrrhotite as remanence carrier may be lower limits because shock demagnetization was not accounted for.
Published: 2016

12. Decrease in coccolithophore calcification and CO2 since the middle Miocene

Author: Maria T. Hernandez-Sanchez, Lorena Abrevaya, Joel E. Johnson, José-Abel Flores, Miguel-Ángel Fuertes, Saúl González-Lemos, Heather Stoll, Ana Mendez-Vicente, Liviu Giosan, Clara T Bolton, Ian Probert, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Geology Department, Oviedo University, Grupo de Geociencias Oceánicas, University of Salamanca, Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics, Woods Hole Oceanographic Institution (WHOI), Department of Earth Sciences [UNH Durham], University of New Hampshire (UNH), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidad de Oviedo [Oviedo], Universidad de Salamanca, Department of Geology and Geophysics [Woods Hole], and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)
Subjects: Alkenone, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Coccolithophore, Oceans and Seas, Science, General Physics and Astronomy, 010502 geochemistry & geophysics, 01 natural sciences, Article, General Biochemistry, Genetics and Molecular Biology, Calcium Carbonate, Carbon Cycle, Carbon cycle, Coccolith, chemistry.chemical_compound, Paleontology, Calcification, Physiologic, Climate science, medicine, Seawater, 14. Life underwater, 0105 earth and related environmental sciences, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, Carbon dioxide in Earth's atmosphere, Multidisciplinary, Ecology, biology, Haptophyta, Ocean acidification, General Chemistry, Biogeochemistry, Carbon Dioxide, Hydrogen-Ion Concentration, biology.organism_classification, medicine.disease, Earth sciences, Oceanography, chemistry, 13. Climate action, Carbon dioxide, Microscopy, Electron, Scanning, Geology, Calcification
Abstract: Marine algae are instrumental in carbon cycling and atmospheric carbon dioxide (CO2) regulation. One group, coccolithophores, uses carbon to photosynthesize and to calcify, covering their cells with chalk platelets (coccoliths). How ocean acidification influences coccolithophore calcification is strongly debated, and the effects of carbonate chemistry changes in the geological past are poorly understood. This paper relates degree of coccolith calcification to cellular calcification, and presents the first records of size-normalized coccolith thickness spanning the last 14 Myr from tropical oceans. Degree of calcification was highest in the low-pH, high-CO2 Miocene ocean, but decreased significantly between 6 and 4 Myr ago. Based on this and concurrent trends in a new alkenone ɛp record, we propose that decreasing CO2 partly drove the observed trend via reduced cellular bicarbonate allocation to calcification. This trend reversed in the late Pleistocene despite low CO2, suggesting an additional regulator of calcification such as alkalinity., The impact of future and past carbonate chemistry changes on calcifying plankton is poorly understood. Here, the authors show that coccolithophore degree of calcification decreased significantly between 6 and 4 million years ago, in line with declining aqueous CO2 concentrations.
Published: 2016

13. Holocene vegetation and climate evolution of Corpus Christi and Trinity bays: Implications on coastal Texas source-to-sink deposition

Author: John B. Anderson, Gilles Escarguel, Alexander R. Simms, Sophie Warny, Shannon Ferguson, Department of Geology and Geophysics, Louisiana State University, Museum of Natural Science, Louisiana State University, Department of Geology and Geophysics and Museum of Natural Science, Louisiana State University [Baton Rouge] ( LSU ), Department of Earth Science, Rice University, Rice University [Houston], Department of Earth Sciences, University of California, University of California [Santa Cruz] ( UCSC ), Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés ( LEHNA ), Institut National de la Recherche Agronomique ( INRA ) -Centre National de la Recherche Scientifique ( CNRS ) -École Nationale des Travaux Publics de l'État ( ENTPE ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon, Louisiana State University (LSU), University of California [Santa Cruz] (UCSC), University of California-University of California, Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)
Subjects: 010506 paleontology, 010504 meteorology & atmospheric sciences, Coastal Texas, Holocene climatic optimum, 01 natural sciences, Deposition (geology), [ SDE ] Environmental Sciences, River terraces, Holocene, Sea level, 0105 earth and related environmental sciences, Palynology, Holocene Coastal Texas Pollen Vegetation Arboreal Gulf of Mexico, [ SDE.BE ] Environmental Sciences/Biodiversity and Ecology, Gulf of Mexico, Evolutionary Biology, Vegetation, Ecology, Paleontology, Geology, 15. Life on land, Climate Action, Geography, Oceanography, 13. Climate action, Space and Planetary Science, Arboreal, [SDE]Environmental Sciences, Pollen, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Bay
Abstract: International audience; The Texas coastline stretches 595 km across almost 48 of latitude and is home to diverse coastal vegetation assemblages, yet only a handful of studies have documented the climate and vegetative change of this region through the Holocene. We provide a detailed palynological record of Holocene climate for coastal Texas, based upon three subaqueous sediment cores from Corpus Christi Bay and Trinity Bay. Cluster analysis and correspondence analysis were used to investigate changes in palynological assemblages through time within each core. Common to both bays are nonarboreal taxa including Asteraceae (mainly Ambrosia and Helianthus), Chenopodium, Poaceae, and arboreal taxa such as Carya, Pinus, and Quercus. Our record shows that the coastal environments of central Texas began a transition from herbaceous (nonarboreal) dominated vegetation to arboreal vegetation as early as 8.4 ka within Corpus Christi Bay, and 3.8 ka within Trinity Bay. We note flooding events at 8.2, 5.4, and 3.6 ka in Corpus Christi Bay, and at 1.7, 1.2, and 0.8 ka in Trinity Bay. These events were caused by storms, sea level changes including flooding of relict river terraces, and changes in sediment delivery to the bays. The pollen record also shows evidence for changes in fluvial discharge to Corpus Christi Bay at 4.1 and 2.2 ka, and at 1.8 ka in Trinity Bay. We also see Zea mays in Trinity Bay, indicating local Native American agriculture. We observe no significant changes during the middle Holocene Climatic Optimum, and subtle but not statistically significant evidence of more variable climate oscillations than other records from more interior sites in Texas available for the late Holocene. This indicates that coastal Texas’ climate has operated semi-independently from central Texas regions, and was primarily driven by a coast-wise gradient of precipitation and evapotranspiration.
Published: 2018

14. Water quantification in silicate glasses by Raman spectroscopy: Correcting for the effects of confocality, density and ferric iron

Author: Taya Flaherty, Federica Schiavi, Etienne Médard, Mickael Laumonier, Alejandra Gómez-Ulla, Nathalie Bolfan-Casanova, Anthony C. Withers, Didier Laporte, Laboratoire Magmas et Volcans ( LMV ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut de Recherche pour le Développement et la société-Université Clermont Auvergne ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Geology and Geophysics, University of Minnesota, 108 Pillsbury Hall, 310 Pillsbury Drive, Minneapolis, Minnesota 55455, U.S.A, University of Minnesota [Minneapolis], ANR-10-LABX-0006/10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism ( 2010 ), Laboratoire Magmas et Volcans (LMV), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement et la société-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Jean Monnet [Saint-Étienne] (UJM), Department of Geology and Geophysics [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)
Subjects: Peak fitting, 010504 meteorology & atmospheric sciences, Confocal Raman spectroscopy, Alumino-silicate glasses, Analytical chemistry, [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography, Water quantification, 010502 geochemistry & geophysics, 01 natural sciences, Spectral line, symbols.namesake, chemistry.chemical_compound, Geochemistry and Petrology, Calibration, Water content, 0105 earth and related environmental sciences, Envelope (waves), [ SDU.STU.PE ] Sciences of the Universe [physics]/Earth Sciences/Petrography, Glass density, Geology, Glass inclusions, chemistry, symbols, Carbonate, Raman spectroscopy, Raman scattering, Intensity (heat transfer)
Abstract: co-auteur étranger; International audience; New series of alumino-silicate glasses spanning a wide range of chemical compositions (basanites, tholeiitic basalts, calcalkaline andesites, peraluminous and peralkaline rhyolites) and with water contents from 0.02 to 6.70 wt% were used for improving the method of quantification of dissolved water with a highly confocal Raman micro-spectrometer. After reconsideration of previously proposed methods for spectra acquisition and post-analysis data treatment, we define the main critical steps that allow minimizing glass matrix effects. First, we carefully assess the variation of Raman band intensities, in both water (~3000–3800 cm−1) and alumino-silicate vibration (~200–1250 cm−1) regions with focus depth of the laser beam inside the sample. Our results indicate that in the first 2–10 μm depth, the intensity increase in the alumino-silicate region is twice as high as that in the water region. Optimal focus depths, where the signal of the water band is maximum and the intensity ratio of the water band to alumino-silicate band is minimum, vary with glass composition and confocal performance of the Raman spectrometer. This influences both external and internal calibration slopes. Second, this study recognizes critical parameters related with glass density, presence of ferric iron and dissolved carbonates as mainly responsible for matrix effects on the internal calibration method. (a) We provide a procedure for correcting the effect of glass density on water internal calibration based on the observation that the integrated intensity (i.e. the area) of the alumino-silicate envelope generally drops with the increase of water content and decrease of glass density. (b) In CO2-bearing glasses, the intensity of the ν1 Raman vibration of dissolved carbonate at ~1087 cm−1 has to be subtracted from the intensity of the alumino-silicate envelope before applying the density correction. (c) Using peak-fitting, the intensity of the 850–1250 cm−1 envelope of peralkaline rhyolitic glasses is corrected for the effect of the presence of four-fold coordinated Fe3+, as revealed by the strong Raman scattering of the vibrational mode at ~980 cm−1. Following this procedure, all the studied glasses define a single calibration line in spite of their compositional variability, when using either of the two classical approaches referred to as external and internal calibration methods. The linear fits of the external and internal calibrations reproduce the whole dataset within 0.13–0.11 wt% (high and standard confocality) and 0.17 wt%, respectively. The accuracy of the external calibration is evaluated based upon comparison with ion-probe measurements of water dissolved in natural glass inclusions: the relative standard deviation is ~4% (1σ) on average, and reaches ~12% (1σ) for water contents of ~0.1 wt%.
Published: 2018

15. Analyse géomorphologique de la déformation d’avant-arc au niveau d’une transition subduction océanique/subduction continentale;

Author: Authemayou, C., Delcaillau, Bernard, Brocard, G., Nexer, M., Molliex, S., Pedoja, Kevin, Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Morphodynamique Continentale et Côtière (M2C), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics [Minnesota], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Institut Universitaire Européen de la Mer ( IUEM ), Institut de Recherche pour le Développement ( IRD ) -Université de Brest ( UBO ) -Centre National de la Recherche Scientifique ( CNRS ), Morphodynamique Continentale et Côtière ( M2C ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Rouen Normandie ( UNIROUEN ), Normandie Université ( NU ) -Normandie Université ( NU ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Université de Caen Normandie ( UNICAEN ), Normandie Université ( NU ), Department of Geology and Geophysics, University of Minnesota [Minneapolis], and Casado-Malaizé, Valérie
Subjects: [SDU] Sciences of the Universe [physics], [SDU]Sciences of the Universe [physics], [ SDU ] Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2016

16. Clinopyroxene in postshield Haleakala ankaramite: 2. Texture, compositional zoning and supersaturation in the magma

Author: Alain Baronnet, S. R. Jacob, John M. Sinton, Julia E. Hammer, Eric Hellebrand, Benoit Welsch, Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics, University of Hawai‘i [Mānoa] (UHM), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), and Department of Geology and Geophysics [Mānoa]
Subjects: Supersaturation, 010504 meteorology & atmospheric sciences, Mineralogy, Magma chamber, 010502 geochemistry & geophysics, 01 natural sciences, law.invention, Dendrite (crystal), Geophysics, Geochemistry and Petrology, law, Magma, Saturation (graph theory), Phenocryst, Ankaramite, Crystallization, Geology, 0105 earth and related environmental sciences, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract: International audience; We investigated the external morphologies and internal compositional zoning patterns of clinopyroxene phenocrysts in an ankaramite of Haleakala volcano (Hawaii) to constrain magma crystallization conditions in the volcano's postshield stage. The phenocrysts are characterized by euhedral faceted morphologies and crystallo-graphically coherent subcrystals. Quantitative EPMA and X-ray element mapping reveal two domains within the crystals: porous, Si-Mg-Ca-Cr-rich zones associated with the forms \100\, \010\ and \110\, and nonporous, Al-Ti-Na-rich zones associated with the forms \-111\. The chemical variations, internal porosity and parallel subcrystals are consistent with nonconcentric crystal growth at varying degrees of supersaturation. We infer that initial growth occurred in a diffusion-limited regime to produce dendritic crystals; subsequent growth was markedly slower, with lesser supersaturation allowing dendrites to infill and produce polyhedral external morphologies. This sequence promoted the evolution of crystals from an hourglass shape with dominant \-111\ forms, to sector-zoned euhedral crystals in which elements were partitioned according to: (Al + Ti + Na)(\-111\) = (Si + Mg + Cr + Ca)(\110\),(\100\),(\010\). Infilling of dendritic crystals occurred to a greater extent on faster-growing sectors and was interrupted by the eruption, resulting in porosity of the slower-growing \hk0\ sectors. Outermost Na-poor rims formed on all sectors due to slower growth rate under interface-limited conditions. Paradoxically, high levels of super-saturation producing large crystals of clinopyroxene (and olivine) are indicated in the volcano's deep-seated reservoir and lower degrees of supersaturation characterize syneruptive crystal growth. The presence of vapor bubbles within the melt-filled crystal embayments and inclusions suggests rapid clinopyroxene growth caused volatile saturation and reservoir pressurization, leading to eruption of the ankaramite.
Published: 2016

17. Hafnium isotopic variations in East Atlantic intraplate volcanism

Author: Barry B. Hanan, Hans-Ulrich Schmincke, Folkmar Hauff, Janne Blichert-Toft, James B. Gill, Kaj Hoernle, Jörg Geldmacher, Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Department of Geological Sciences [San Diego], San Diego State University (SDSU), Laboratoire de Sciences de la Terre (LST), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), IfM-GEOMAR Leibniz Institute for Marine Sciences, Dynamics of the Ocean Floor, Integrated Ocean Drilling Program, Texas A&M University [College Station], Department of Geology and Geophysics, Leibniz Institute of Marine Science at the University of Kiel (IFM-GEOMAR), Kiel University, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Department of Earth and Planetary Sciences [Santa Cruz], University of California [Santa Cruz] (UCSC), University of California-University of California, Deutsche Forschungsgemeinschaft (DFG, German Research Council) : Ho 1833/1, Ho 1833/9, Bundesministerium fur Bildung, Wissenschaft, Forschung and Technology (BMBF, Federal Ministry of Education and Research), National Science Foundation (NSF), INSU : Institut des Science de l'Univers, DFG : SCHM 250/82-1, GE 1125/1-1, Department of Geology and Geophysics [College Station], Department of Geological Sciences [San Diego State Univ] (Geology SDSU), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), University of California [Santa Cruz] (UC Santa Cruz), and University of California (UC)-University of California (UC)
Subjects: [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDE.MCG]Environmental Sciences/Global Changes, Seamount, Geochemistry, Canary Islands, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Volcanism, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), Madeira, East Central Atlantic, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Geochemistry and Petrology, Hotspot (geology), 14. Life underwater, 010503 geology, ComputingMilieux_MISCELLANEOUS, Hf-isotopes, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Radiogenic nuclide, Subduction, Mantle geochemistry, Volcanic rock, Geophysics, 13. Climate action, Intraplate earthquake, Hotspots, Geology, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract: International audience; The broad belt of intraplate volcanism in the East Atlantic between 25A degrees and 37A degrees N is proposed to have formed by two adjacent hotspot tracks (the Madeira and Canary tracks) that possess systematically different isotopic signatures reflecting different mantle source compositions. To test this model, Hf isotope ratios from volcanic rocks from all individual islands and all major seamounts are presented in this study. In comparison with published Nd isotope variations (6 epsilon Nd units), (176)Hf/(177)Hf ratios span a much larger range (14 epsilon Hf units). Samples from the proposed Madeira hotspot track have the most radiogenic Hf isotopic compositions ((176)Hf/(177)Hf(m) up to 0.283335), extending across the entire field for central Atlantic MORB. They form a relatively narrow, elongated trend on the Nd vs. Hf isotope diagram (stretching over > 10 epsilon Hf units) between a depleted N-MORB-like endmember and a moderately enriched composition located on, or slightly below, the Nd-Hf mantle array, which overlaps the proposed "C" mantle component of Hanan and Graham (1996). In contrast, all samples from the Canary hotspot track plot below the mantle array ((176)Hf/(177)Hf(m) = 0.282943-0.283067) and form a much denser cluster with less compositional variation (similar to 4 epsilon Hf units). The cluster falls between (1) a low Hf isotope HIMU-like endmember, (2) a more depleted composition, and (3) the moderately enriched end of the Madeira trend. The new Hf isotope data confirm the general geochemical distinction of the Canary and Madeira domains in the East Atlantic. Both domains, however, seem to share a common, moderately enriched endmember that has "C"-like isotope compositions and is believed to represent subducted, < 1-Ga-old oceanic lithosphere (oceanic crust and possibly minor sediment addition). The lower (176)Hf/(177)Hf ratio of the enriched, HIMU-like Canary domain endmember indicates the contribution of oceanic lithosphere with somewhat older recycling ages of a parts per thousand yen1 Ga
Published: 2010

18. Atmospheric forcing dominates winter Barents-Kara sea ice variability on interannual to decadal time scales

Author: Zhongfang Liu, Camille Risi, Francis Codron, Zhimin Jian, Zhongwang Wei, Xiaogang He, Christopher J. Poulsen, Yue Wang, Dong Chen, Wentao Ma, Yanyan Cheng, Gabriel J. Bowen, State Key Laboratory of Marine Geology [Shanghai], Tongji University, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Océan et variabilité du climat (VARCLIM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Department of Civil and Environmental Engineering [Singapore], National University of Singapore (NUS), Department of Earth and Environmental Sciences [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Nansen-Zhu International Research Centre, Institute of Atmospheric Physics [Beijing] (IAP), Chinese Academy of Sciences [Beijing] (CAS)-Chinese Academy of Sciences [Beijing] (CAS), State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Department of Geology and Geophysics, and University of Utah
Subjects: Multidisciplinary, [SDU]Sciences of the Universe [physics], Arctic Regions, Atmosphere, Climate, Oceans and Seas, Ice Cover, Seasons, Time
Abstract: The last two decades have seen a dramatic decline and strong year-to-year variability in Arctic winter sea ice, especially in the Barents-Kara Sea (BKS), changes that have been linked to extreme midlatitude weather and climate. It has been suggested that these changes in winter sea ice arise largely from a combined effect of oceanic and atmospheric processes, but the relative importance of these processes is not well established. Here, we explore the role of atmospheric circulation patterns on BKS winter sea ice variability and trends using observations and climate model simulations. We find that BKS winter sea ice variability is primarily driven by a strong anticyclonic anomaly over the region, which explains more than 50% of the interannual variability in BKS sea-ice concentration (SIC). Recent intensification of the anticyclonic anomaly has warmed and moistened the lower atmosphere in the BKS by poleward transport of moist-static energy and local processes, resulting in an increase in downwelling longwave radiation. Our results demonstrate that the observed BKS winter sea-ice variability is primarily driven by atmospheric, rather than oceanic, processes and suggest a persistent role of atmospheric forcing in future Arctic winter sea ice loss.
Published: 2023

19. Geomorphologic Indices for Transition from Subduction to Arc-Continent Collision in Sumba Island, Indonesia

Author: Authemayou, C., Delcaillau, Bernard, Brocard, G., Molliex, S., Nexer, M., Pedoja, Kevin, Institut Universitaire Européen de la Mer ( IUEM ), Institut de Recherche pour le Développement ( IRD ) -Université de Brest ( UBO ) -Centre National de la Recherche Scientifique ( CNRS ), Morphodynamique Continentale et Côtière ( M2C ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Rouen Normandie ( UNIROUEN ), Normandie Université ( NU ) -Normandie Université ( NU ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Université de Caen Normandie ( UNICAEN ), Normandie Université ( NU ), Department of Geology and Geophysics, University of Minnesota [Minneapolis], Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Morphodynamique Continentale et Côtière (M2C), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics [Minnesota], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, and Casado-Malaizé, Valérie
Subjects: [SDU] Sciences of the Universe [physics], [SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS, [ SDU ] Sciences of the Universe [physics]
Abstract: International audience
Published: 2014

20. Source partitioning of anthropogenic groundwater nitrogen in a mixed-use landscape, Tutuila, American Samoa

Author: Fackrell, Joseph [University of Hawaii at Manoa, Department of Geology and Geophysics (United States)]
Published: 2017
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21. Morphology and dynamics of inflated subaqueous basaltic lava flows

Author: Anne Deschamps, Cécile Grigné, Morgane Le Saout, Samuel Adam Soule, Pascal Allemand, Brigitte Van Vliet-Lanoe, France Floc'h, Domaines Océaniques (LDO), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics, Woods Hole Oceanographic Institution (WHOI), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Department of Geology and Geophysics [Woods Hole], Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, cooling, Lava, [SDE.MCG]Environmental Sciences/Global Changes, Subaerial eruption, 010502 geochemistry & geophysics, 01 natural sciences, Effusive eruption, Lava field, Geochemistry and Petrology, Pahoehoe, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, tumulus, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, inflation, Petrology, Geomorphology, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Lava dome, eruption, Geophysics, Shield volcano, Gas slug, Subaerial, East Pacific rise, Geology
Abstract: International audience; During eruptions onto low slopes, basaltic Pahoehoe lava can form thin lobes that progressively coalesce and inflate to many times their original thickness, due to a steady injection of magma beneath brittle and viscoelastic layers of cooled lava that develop sufficient strength to retain the flow. Inflated lava flows forming tumuli and pressure ridges have been reported in different kinds of environments, such as at contemporary subaerial Hawaiian-type volcanoes in Hawaii, La Réunion and Iceland, in continental environments (states of Oregon, Idaho, Washington), and in the deep sea at Juan de Fuca Ridge, the Galapagos spreading center, and at the East Pacific Rise (this study). These lava have all undergone inflation processes, yet they display highly contrasting morphologies that correlate with their depositional environment, the most striking difference being the presence of water. Lava that have inflated in subaerial environments display inflation structures with morphologies that significantly differ from subaqueous lava emplaced in the deep sea, lakes, and rivers. Their height is 2-3 times smaller and their length being 10-15 times shorter. Based on heat diffusion equation, we demonstrate that more efficient cooling of a lava flow in water leads to the rapid development of thicker (by 25%) cooled layer at the flow surface, which has greater yield strength to counteract its internal hydrostatic pressure than in subaerial environments, thus limiting lava breakouts to form new lobes, hence promoting inflation. Buoyancy also increases the ability of a lava to inflate by 60%. Together, these differences can account for the observed variations in the thickness and extent of subaerial and subaqueous inflated lava flows.
Published: 2014

22. Hydration of mantle olivine under variable water and oxygen fugacity conditions

Author: Gaetani, Glenn A., Leary, Julie A. O., Kenneth T. Koga, Hauri, Erik H., Estelle Rose-Koga, Manteleone, Brian D., Department of Geology and Geophysics [USA], Woods Hole Oceanographic Institution (WHOI), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Terrestrial Magnetism [Carnegie Institution], Carnegie Institution for Science [Washington], Department of Geology and Geophysics [Woods Hole], Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Carnegie Institution for Science, and Jouhannel, Sylvaine
Subjects: minerals Upper mantle, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Olivine, [SDU.STU.GC] Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography, [SDU.STU.PE] Sciences of the Universe [physics]/Earth Sciences/Petrography, Nominally anhydrous
Abstract: International audience; The incorporation of H into olivine is influenced by a significant number of thermodynamic variables (pressure, temperature, oxygen fugacity, etc.). Given the strong influence that H has on the solidus temperature and rheological behavior of mantle peridotite, it is necessary to determine its solubility in olivine over the range of conditions found in the upper mantle. This study presents results from hydration experiments carried out to determine the effects of pressure, temperature, and the fugacities of H2O and O2 on H solubility in San Carlos olivine at upper mantle conditions. Experiments were carried out at 1–2 GPa and 1,200 °C using a piston-cylinder device. The fugacity of O2 was controlled at the Fe0–FeO, FeO–Fe3O4, or Ni0–NiO buffer. Variable duration experiments indicate that equilibration is achieved within 6 h. Hydrogen contents of the experimental products were measured by secondary ion mass spectrometry, and relative changes to the point defect populations were investigated using Fourier transform infrared spectroscopy. Results from our experiments demonstrate that H solubility in San Carlos olivine is sensitive to pressure, the activity of SiO2, and the fugacities of H2O and O2. Of these variables, the fugacity of H2O has the strongest influence. The solubility of H in olivine increases with increasing SiO2 activity, indicating incorporation into vacancies on octahedral lattice sites. The forsterite content of the olivine has no discernible effect on H solubility between 88.17 and 91.41, and there is no correlation between the concentrations of Ti and H. Further, in all but one of our experimentally hydrated olivines, the concentration of Ti is too low for H to be incorporated dominantly as a Ti-clinohumite-like defect. Our experimentally hydrated olivines are characterized by strong infrared absorption peaks at wavenumbers of 3,330, 3,356, 3,525, and 3,572 cm−1. The heights of peaks at 3,330 and 3,356 cm−1 correlate positively with O2 fugacity, while those at 3,525 and 3,572 cm−1 correlate with H2O fugacity.
Published: 2014

23. Effects of Chemistry on Vertical Dust Motion in Early Protoplanetary Disks

Author: Korenaga, Jun [Department of Geology and Geophysics, Yale University, New Haven, CT (United States)]
Published: 2017
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24. The influence of wavelength-dependent absorption and temperature gradients on temperature determination in laser-heated diamond-anvil cells

Author: Lee, Kanani [Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520, USA] (ORCID:0000000330034802)
Published: 2017
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25. On the Time Scales of Magma Genesis, Melt Evolution, Crystal Growth Rates and Magma Degassing in the Erebus Volcano Magmatic System Using the 238U, 235U and 232Th Decay Series

Author: G. M. Sawyer, Graham D. Layne, Henrietta Dulaiova, Sylvain Pichat, Philip R. Kyle, Nelia W. Dunbar, Matthew A. Charette, Tim Elliott, Mark K. Reagan, Janne Blichert-Toft, Kenneth W.W. Sims, Julie Prytulak, Pierre J. Gauthier, Laboratoire de Sciences de la Terre (LST), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), New Mexico Institute of Mining and Technology [New Mexico Tech] (NMT), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford, École normale supérieure de Lyon (ENS de Lyon), Woods Hole Oceanographic Institution (WHOI), Wyoming High-Precision Isotope Laboratory, Department of Geology and Geophysics, University of Wyoming ( UW ), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] ( LGL-TPE ), École normale supérieure - Lyon ( ENS Lyon ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Geosciences, University of Iowa [Iowa], Department of Earth and Environmental Sciences, New Mexico Institute of Mining and Technology [New Mexico Tech] ( NMT ), Department of Geology and Geophysics, University of Hawai, Department of Atmospheric, Oceanic and Planetary Physics [Oxford] ( AOPP ), University of Oxford [Oxford], School of Earth Sciences [Bristol], University of Bristol [Bristol], Department of Geography [Cambridge, UK], University of Cambridge [UK] ( CAM ), Department of Earth Sciences, Memorial University of Newfoundland [St. John's], Laboratoire Magmas et Volcans ( LMV ), Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Marine Chemistry and Geochemistry ( WHOI ), Woods Hole Oceanographic Institution ( WHOI ), University of Wyoming (UW), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), University of Iowa [Iowa City], Department of Earth and Environmental Science [Socorro], University of Hawai‘i [Mānoa] (UHM), University of Cambridge [UK] (CAM), Department of Earth Sciences [St. John's], Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Marine Chemistry and Geochemistry (WHOI), École normale supérieure - Lyon (ENS Lyon), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Memorial University of Newfoundland = Université Memorial de Terre-Neuve [St. John's, Canada] (MUN), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: HIMU, 010504 meteorology & atmospheric sciences, Lava, [SDE.MCG]Environmental Sciences/Global Changes, Anorthoclase, Geochemistry, U-series isotopes, Magma chamber, engineering.material, 010502 geochemistry & geophysics, magma chamber residence time, 01 natural sciences, Erebus volcano, Geochemistry and Petrology, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Phonolite, biology, Erebus, [ SDU.STU.GC ] Sciences of the Universe [physics]/Earth Sciences/Geochemistry, biology.organism_classification, Strombolian eruption, open-system crystallization, [ SDE.MCG ] Environmental Sciences/Global Changes, Geophysics, 13. Climate action, Magma, engineering, Antarctica, Volcanic bomb, magma degassing, Geology
Abstract: International audience; We investigate the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the Erebus volcano magmatic system using measurements of 238U-230Th-226Ra-210Pb-210Po, 232Th-228Ra-228Th and 235U-231Pa-227Ac. These are the first measurements of 231Pa-227Ac in volcanic samples and represent the first set of data in a volcanic system to examine the entire suite of relevant 238U, 235U and 232Th decay series nuclides. Our sample suite consists of 22 phonolite volcanic bombs, erupted between 1972 and 2005, and five anorthoclase megacrysts separated from bombs erupted in 1984, 1989, 1993, 2004 and 2005. The 238U-230Th, 230Th-226Ra and 235U-231Pa systems are uniform over the 34 years examined. The anorthoclase megacrysts and phonolite glasses show complementary 226Ra/230Th disequilibria with (226Ra/230Th) ∼40 in the anorthoclase and ∼0*75 in the phonolite glass. In all samples, (210Pb/226Ra) is in radioactive equilibrium for both phases. In two phonolite glass samples (227Ac/231Pa) is unity. For the phonolite glasses (228Ra/232Th) is in equilibrium, whereas in the anorthoclase megacrysts it is significantly greater than unity. Instantaneous crystal fractionation, with magma residence times greater than 100 years and less than 10 kyr, can account for the measured 238U-230Th-226Ra-210Pb and 235U-231Pa-227Ac. However, the significant 228Ra/232Th disequilibria in the anorthoclase megacrysts preclude this simple interpretation. To account for this apparent discrepancy we therefore developed an open-system, continuous crystallization model that incorporates both nuclide ingrowth and decay during crystallization. This open-system model successfully reproduces all of the measured 238U and 232Th disequilibria and suggests that the shallow magma reservoir at Erebus is growing. The implication of this modeling is that when the time scale of crystallization is comparable with the half-life of the daughter nuclide of interest (e.g. 226Ra) the simple isochron techniques typically used in most U-series studies can provide erroneous ages. The observation that (210Pb/226Ra) and (227Ac/231Pa) are in radioactive equilibrium suggests that the residence time of the magmas is >100 years. When considering the effect of 222Rn degassing on 210Pb/226Ra, the data indicate that the majority of magma degassing is deep and long before eruption, consistent with melt inclusion data. Additionally, for the 2005 lava bomb, whose eruption date (16 December 2005) is known explicitly, 210Po was not completely degassed from the magma at the time of eruption. Incomplete degassing of 210Po is atypical for subaerially erupted lavas and suggests that the Erebus shallow magma degasses about 1% of its Po per day. The combined 238U and 232Th data further indicate that the pyroclasts ejected by Strombolian eruptions at Erebus have compositions that are close to what would be expected for a near-steady-state system, reflecting inmixing of degassed magmas, crystal fractionation, and aging.
Published: 2013

26. The stable vanadium isotope composition of the mantle and mafic lavas

Author: Jason Harvey, Alex N. Halliday, Kenji Shimizu, Katherine A. Kelley, Dmitri A. Ionov, Yaoling Niu, Sune G. Nielsen, Julie Prytulak, Kenneth W.W. Sims, David W. Peate, Department of Atmospheric, Oceanic and Planetary Physics [Oxford] ( AOPP ), University of Oxford [Oxford], School of Earth Sciences [Bristol], University of Bristol [Bristol], Department of Earth Sciences, Department of Geology & Geophysics, Woods Hole Oceanographic Institution ( WHOI ), Laboratoire Magmas et Volcans ( LMV ), Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Centre National de la Recherche Scientifique ( CNRS ), Institute of Geophysics and Tectonics, School of Earth and Environment, University of Leeds, Graduate School of Oceanography, University of Rhode Island ( URI ), Department of Earth Science, University of Durham, Department of Geosciences, University of Iowa [Iowa], Institute for Research on Earth Evolution, Japan Agency of Marine-Earth, Department of Geology and Geophysics [Laramie], University of Wyoming ( UW ), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), Department of Earth Sciences [Oxford], Woods Hole Oceanographic Institution (WHOI), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Graduate School of Oceanography [Narragansett], University of Rhode Island (URI), Durham University, University of Iowa [Iowa City], Institute for Research on Earth Evolution [Yokosuka] (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), University of Wyoming (UW), University of Oxford, Department of Geology and Geophysics [Woods Hole], Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)
Subjects: 010504 meteorology & atmospheric sciences, vanadium isotopes, Large igneous province, [SDE.MCG]Environmental Sciences/Global Changes, Geochemistry, Mineralogy, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), high temperature stable isotope fractionation, chemistry.chemical_compound, Geochemistry and Petrology, Ultramafic rock, Mineral redox buffer, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Earth and Planetary Sciences (miscellaneous), 0105 earth and related environmental sciences, Basalt, Partial melting, bulk silicate Earth, [ SDU.STU.GC ] Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Silicate, [ SDE.MCG ] Environmental Sciences/Global Changes, Geophysics, chemistry, 13. Climate action, Space and Planetary Science, Mafic, Geology
Abstract: International audience; Vanadium exists in multiple valence states under terrestrial conditions (2+, 3+, 4+, 5+) and its isotopic composition in magmas potentially reflects the oxidation state of their mantle source. We present the first stable vanadium isotope measurements of 64 samples of well-characterized mantle-derived mafic and ultramafic rocks from diverse localities. The δ51V ranges from −0.27‰ to −1.29‰, reported relative to an Alfa Aesar (AA) vanadium solution standard defined as 0‰. This dataset is used to assess the effects of alteration, examine co-variation with other geochemical characteristics and define a value for the bulk silicate Earth (BSE). Variably serpentinised peridotites show no resolvable alteration-induced δ51V fractionation. Likewise, altered mafic oceanic crustal rocks have identical δ51V to fresh hand-picked MORB glass. Intense seafloor weathering can result in slightly (∼0.2-0.3‰) heavier isotope compositions, possibly related to late-stage addition of vanadium. The robustness of δ51V to common alteration processes bodes well for its potential application to ancient mafic material. The average δ51V of mafic lavas, including MORB, Icelandic tholeiites and lavas from the Shatsky Rise large igneous province is −0.88±0.27‰ 2sd. Peridotites show a large range in primary δ51V (−0.62‰ to −1.17‰), which co-varies positively with vanadium concentrations and indices of fertility such as Al2O3. Although these data suggest preferential extraction of heavier isotopes during partial melting, the isotope composition of basalts (δ51V=−0.88±0.27‰ 2sd) and MORB glass in particular (δ51V=−0.95±0.13‰ 2sd) is lighter than fertile peridotites and thus difficult to reconcile with a melt extraction scenario. Determination of fractionation factors between melt and mineral phases such as pyroxenes and garnet are necessary to fully understand the correlation. We arrive at an estimate of δ51VBSE=−0.7±0.2‰ (2sd) for the bulk silicate Earth by averaging fertile, unmetasomatised peridotites. This provides a benchmark for both high and low temperature applications addressing planet formation, cosmochemical comparisons of the Earth and extraterrestrial material, and an inorganic baseline for future biogeochemical investigations. Whilst δ51V could relate to oxidation state and thus oxygen fugacity, further work is required to resolve the isotopic effects of oxidation state, partial melting, and mineral fractionation factors.
Published: 2013

27. Compression of a multiphase mantle assemblage: Effects of undesirable stress and stress annealing on the iron spin state crossover in ferropericlase: Stresses and HS-LS Crossover in (Mg,Fe)O

Author: Lee, Kanani [Department of Geology and Geophysics, Yale University, New Haven Connecticut USA]
Published: 2016
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28. Influence of incision rate, rock strength, and bedload supply on bedrock river gradients and valley-flat widths: Field-based evidence and calibrations from western Alpine rivers (southeast France)

Author: Gilles Brocard, P.A. van der Beek, Laboratoire de Géodynamique des Chaines Alpines (LGCA), Observatoire des Sciences de l'Univers de Grenoble [1985-2015] (OSUG [1985-2015]), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut des Sciences de la Terre [2011-2015] (ISTerre [2011-2015]), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics, University of Minnesota [Twin Cities], University of Minnesota System-University of Minnesota System, Willett, S.D., Hovius, N., Brandon, M.T., and Fisher, D., Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics [Minneapolis], University of Minnesota [Twin Cities] (UMN), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut des Sciences de la Terre (ISTerre), and Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)
Subjects: landscape evolution, 010504 meteorology & atmospheric sciences, Drainage basin, Fluvial, 010502 geochemistry & geophysics, 01 natural sciences, Bedrock river, sediment supply, fluvial geomorphology, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Geomorphology, Stream power, 0105 earth and related environmental sciences, Hydrology, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, geography, geography.geographical_feature_category, Landform, Bedrock, 15. Life on land, river incision, valley width, Alluvium, Channel (geography), Geology
Abstract: Several process-based models of river incision have been proposed in recent years that attempt to describe fluvial landform development. Although some field tests have been performed, more data are required to test the ability of these models to predict the observed evolution of fluvial landforms. We have investigated several tens of rivers located in the French western Alps that flow across folded sedimentary rocks with strongly contrasting rock strengths. These rivers record significant variations in some of the parameters controlling river incision, notably bedrock lithology, stream power, incision rate, and sediment flux, potentially allowing discrimination between existing models. Variations in incision rates are driven by variations in the amount of disequilibrium introduced in the river profiles during the last glaciation. We use diagnostic indices to investigate transport- and detachment-limited conditions, which include the channel morphology, the occurrence of lithogenic knickpoints, the continuity of alluvial and bedrock reaches, and the slope-area scaling of the river long profile. We observe transitions from detachment-limited to transport-limited conditions with increasing discharge/drainage area and decreasing incision rate. Bedrock strength influences the location of the transition predictably. The formation of transport-limited rivers coincides with the development of a valley flat wider than the active channel, which accommodates variations in bedrock strength, stream power, and incision rate along the transport-limited reaches. We propose and calibrate a model for the development of valley flats along transport-limited rivers and explore some properties of landscape development in mountain ranges controlled by transport-limited rivers.
Published: 2006

29. Testing the direct effect of CO2 concentration on a bloom of the coccolithophorid Emiliania huxleyi in mesocosm experiments

Author: Albert Benthien, U. Schneider, Linn Hoffmann, Christel Heemann, Anja Terbrueggen, Bruno Delille, Lei Chou, Luc Beaufort, Stéphan Jacquet, Anja Engel, Jean-Pierre Gattuso, Emma Rochelle-Newall, Jens C. Nejstgaard, Ulf Riebesell, Jérôme Harlay, Katrien Aerts, Marie-Dominique Pizay, Ingrid Zondervan, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Unité d'Océanographie Chimique, Interfacultary Center for Marine Research (MARE), Université de Liège-Université de Liège, Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL), Institut National de la Recherche Agronomique (INRA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Laboratoire de Physique et Chimie Marines (LPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Inconnu, Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Partenaires INRAE, State University of New York (SUNY), Department of Chemistry, University of Antwerp (UA), Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics, Woods Hole Oceanographic Institution (WHOI), Université libre de Bruxelles (ULB), University of Bergen (UiB), Université Pierre et Marie Curie - Paris 6 (UPMC), Institut de Recherche pour le Développement (IRD), Leibniz Institute of Marine Sciences, Wischhofstr. 1&ndash, Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), and Department of Geology and Geophysics [Woods Hole]
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, CONCENTRATION EN CO2, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Aquatic Science, Biology, [SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study, Oceanography, 01 natural sciences, Mesocosm, chemistry.chemical_compound, Nitrate, marine biogeochemistry, Botany, cell physiology, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Emiliania huxleyi, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010604 marine biology & hydrobiology, fungi, Biogeochemistry, Plankton, biology.organism_classification, chemistry, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Environmental chemistry, Carbon dioxide, Seawater, Bloom, [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology
Abstract: International audience; We studied the direct effects of CO, and related changes in seawater carbonate chemistry on marine planktonic organisms in a mesocosm experiment. In nine outdoor enclosures (similar to 11 m(3) each), the partial pressure of CO2 (pCO(2)) in the seawater was modified by an aeration system. The triplicate mesocosm treatments represented low (similar to 190 parts per million by volume (ppmV) CO2), present (similar to 410 ppmV CO2), and high (similar to 710 ppmV CO2) pCO(2) conditions. After initial fertilization with nitrate and phosphate a bloom dominated by the coccolithophorid Emiliania huxleyi occurred simultaneously in all of the nine mesocosms; it was monitored over a 19-day period, The three CO2 treatments assimilated nitrate and phosphate similarly. The concentration of particulate constituents was highly variable among the replicate mesocosms, disguising direct CO2-related effects. Normalization of production rates within each treatment, however, indicated that the net specific growth rate of E. huxleyi, the rate of calcification per cell, and the elemental stoichiometry of uptake and production processes were sensitive to changes in pCO(2). This broad influence of CO2 on the E huxleyi bloom suggests that changes in CO2 concentration directly affect cell physiology with likely effects on the marine biogeochemistry.
Published: 2005

30. Calcium isotopic ecology of Turkana Basin hominins

Author: Jeremy E, Martin, Théo, Tacail, José, Braga, Thure E, Cerling, Vincent, Balter, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Anthropologie Moléculaire et Imagerie de Synthèse (AMIS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics, Global Change and Sustainability Center, University of Utah, Salt Lake City, UT 84112, United States, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées
Subjects: Calcium Isotopes, Carbon Isotopes, Stable isotope analysis, Ecology, Fossils, Biological anthropology, Palaeontology, Science, Palaeoecology, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Hominidae, Kenya, Article, stomatognathic diseases, stomatognathic system, [SDU]Sciences of the Universe [physics], Animals, lcsh:Q, [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology, lcsh:Science, History, Ancient
Abstract: Diet is a major driver of hominin evolution, but most of the geochemical evidence relies on carbon isotopes (δ13C). Here, we report enamel stable calcium isotope (δ44/42Ca) values against δ13C values for several hominins and co-existing primates in the Turkana Basin area, circa 4 to 2 Ma. Australopithecus anamensis clusters with mammal browsers, Kenyanthropus platyops is distinct from A. anamensis in foraging into more open environments and the coexisting Theropithecus brumpti encompasses both the grazer and omnivore/carnivore domains. Early Homo is remarkable for its wide distribution in δ44/42Ca values, possibly reflecting omnivorous and opportunistic preferences. Paranthropus boisei is uniquely distributed in the δ13C versus δ44/42Ca iso-space being distinct from all other hominins from the Turkana Basin area as well as from the co-existing Theropithecus oswaldi. Several hypotheses are explored to discuss the unique δ44/42Ca values of Paranthropus boisei including significant differences observed with δ44/42Ca values recently reported for P. robustus from South Africa, questioning the monophyly of this genus., Non-traditional stable isotopes, such as of calcium, have potential to expand our understanding of ancient diets. Here, Martin et al. use stable calcium isotopes recovered from fossil tooth enamel to compare the dietary ecology of hominins and other primates in the Turkana Basin 2-4 million years ago.
Published: 2020

31. Correction to: Persistent freshening of the Arctic Ocean and changes in the North Atlantic salinity caused by Arctic sea ice decline

Author: Hui Li, Alexey V. Fedorov, National Center for Atmospheric Research [Boulder] (NCAR), Océan et variabilité du climat (VARCLIM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Department of Geology and Geophysics [New Haven], and Yale University [New Haven]
Subjects: Atmospheric Science, [SDU]Sciences of the Universe [physics]
Abstract: International audience
Published: 2022

32. A STATISTICAL RECONSTRUCTION OF THE PLANET POPULATION AROUND KEPLER SOLAR-TYPE STARS

Author: Gaidos, Eric [Department of Geology and Geophysics, University of Hawai'i at Mānoa, Honolulu, HI 96822 (United States)]
Published: 2015
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33. The Nazca Drift System – palaeoceanographic significance of a giant sleeping on the SE Pacific Ocean floor

Author: Liviu Giosan, Alan C. Mix, M. Vega, Patrice Baby, Gérôme Calvès, Peter D. Clift, Stéphane Brusset, Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Oregon State University, Corvallis, USA, Geology and Geophysics Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA, Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA, Louisiana State University (LSU), Institut de Recherche pour le Développement (IRD), Universidad Nacional de San Antonio Abad del Cusco (UNSAAC), and Université de Toulouse (UT)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Oceanography, 010504 meteorology & atmospheric sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Geology, 14. Life underwater, 010502 geochemistry & geophysics, 01 natural sciences, Pacific ocean, 0105 earth and related environmental sciences
Abstract: The evolution and resulting morphology of a contourite drift system in the SE Pacific oceanic basin is investigated in detail using seismic imaging and an age-calibrated borehole section. The Nazca Drift System covers an area of 204 500 km2 and stands above the abyssal basins of Peru and Chile. The drift is spread along the Nazca Ridge in water depths between 2090 and 5330 m. The Nazca Drift System was drilled at Ocean Drilling Program Site 1237. This deep-water drift overlies faulted oceanic crust and onlaps associated volcanic highs. Its thickness ranges from 104 to 375 m. The seismic sheet facies observed are associated with bottom current processes. The main lithologies are pelagic carbonates reflecting the distal position relative to South America and water depth above the carbonate compensation depth during Oligocene time. The Nazca Drift System developed under the influence of bottom currents sourced from the Circumpolar Deep Water and Pacific Central Water, and is the largest yet identified abyssal drift system of the Pacific Ocean, ranking third in all abyssal contourite drift systems globally. Subduction since late Miocene time and the excess of sediments and water associated with the Nazca Drift System may have contributed to the Andean orogeny and associated metallogenesis. The Nazca Drift System records the evolution in interactions between deep-sea currents and the eastward motion of the Nazca Plate through erosive surfaces and sediment remobilization.
Published: 2021

34. TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet

Author: Andrés Jordán, Sara Seager, Brett C. Addison, Maximilian N. Günther, Monika Lendl, Jack Okumura, Jorge Lillo-Box, Jon M. Jenkins, Roland Vanderspek, C. G. Tinney, Benjamin J. Fulton, Peter J. Wheatley, Erik A. Petigura, Beth A. Henderson, C. Stibbard, P. Figueira, Rafael Brahm, Eric L. N. Jensen, Michael Reefe, Cesar Briceno, Chris Stockdale, S. Hojjatpanah, Farisa Y. Morales, Alexis M. S. Smith, Caroline Dorn, Thomas Henning, Vardan Adibekyan, George W. King, Lauren M. Weiss, David R. Ciardi, Howard Isaacson, Richard P. Schwarz, Thomas Barclay, Stephen R. Kane, Keivan G. Stassun, David W. Latham, Malcolm Fridlund, Jack S. Acton, Ravit Helled, Sharon X. Wang, John Berberian, Joseph D. Twicken, J. F. Otegi, David R. Anderson, Sarah L. Casewell, Elise Furlan, Elisabeth Matthews, Johanna Teske, Rodrigo F. Díaz, Samuel Gill, Daniel Bayliss, Ian Crossfield, Peter Plavchan, Matthew W. Mengel, Joshua E. Schlieder, John F. Kielkopf, Stéphane Udry, E. Delgado Mena, H. P. Osborn, Avi Shporer, R. Cloutier, J. Villasenor, Duncan J. Wright, E. Gaidos, A. Osborn, K. I. Collins, Angelle Tanner, Nicholas M. Law, Björn Benneke, Joshua N. Winn, Fei Dai, Nicholas J. Scott, Erica J. Gonzales, Courtney D. Dressing, Sarah Ballard, Don Pollacco, Coel Hellier, Michael R. Goad, David J. Armstrong, Varoujan Gorjian, Paula Sarkis, Richard C. Kidwell, F. Zohrabi, Nuno C. Santos, David Barrado, Matthew R. Burleigh, Sergio Hoyer, Claire Geneser, Christopher J. Burke, Richard G. West, James McCormac, P. A. Strøm, Daniel Huber, Aleisha Hogan, Paul Robertson, Natalie M. Batalha, Edward M. Bryant, Liam Raynard, Karen A. Collins, Robert A. Wittenmyer, Mark E. Rose, Rachel A. Matson, Steve B. Howell, James S. Jenkins, Jose I. Vines, S. C. C. Barros, Néstor Espinoza, B. Cale, Andrew W. Howard, Diana Dragomir, Alexandre Santerne, M. Lund, Olivier Demangeon, Brendan P. Bowler, Benjamin F. Cooke, Xavier Dumusque, Andrew W. Mann, Hui Zhang, Carl Ziegler, Arpita Roy, Rosanna H. Tilbrook, Sérgio F. Sousa, George R. Ricker, Jonathan Horner, Elisa V. Quintana, Thiam-Guan Tan, Louise D. Nielsen, François Bouchy, University of New South Wales [Sydney] (UNSW), McDonald Observatory, University of Texas at Austin [Austin], Leiden Observatory [Leiden], Universiteit Leiden, Chalmers University of Technology [Gothenburg, Sweden], NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Instituto de Astrofísica e Ciências do Espaço (IASTRO), Center for Space Research [Cambridge] (CSR), Massachusetts Institute of Technology (MIT), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Département de Physique [Montréal], Université de Montréal (UdeM), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Leicester], University of Leicester, Infrared Processing and Analysis Center (IPAC), California Institute of Technology (CALTECH), Optimisation - Système - Energie (GEPEA-OSE), Laboratoire de génie des procédés - environnement - agroalimentaire (GEPEA), Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Université de Nantes (UN)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN), Institut für Virologie, Philipps University, MIT Kavli Institute for Astrophysics and Space Research, Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Department of Geology and Geophysics [Mānoa], University of Hawai‘i [Mānoa] (UHM), Universität Zürich [Zürich] = University of Zurich (UZH), Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Universidad de Chile = University of Chile [Santiago] (UCHILE), Pontificia Universidad Católica de Chile (UC), University of Louisville, Austrian Academy of Sciences (OeAW), Lund University [Lund], University of Warwick [Coventry], Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), German Aerospace Center (DLR), Swiss Bee Research Centre, Centre for Medical Image Computing (CMIC), and University College of London [London] (UCL)
Subjects: (TOI-431, planets and satellites: detection, Fundamental Parameters, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], (TOI-431, TIC 31374837), FOS: Physical sciences, Individual, Astrophysics, Q1, 01 natural sciences, Neptune, Planet, QB460, 0103 physical sciences, planets and satellites: fundamental parameters, 010303 astronomy & astrophysics, QB600, QC, 0105 earth and related environmental sciences, QB, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Super-Earth, Astronomy and Astrophysics, Planets and Satellites, Radius, Light curve, Exoplanet, Radial velocity, Photometry (astronomy), Detection, 13. Climate action, Space and Planetary Science, planets and satellites: individual: (TOI-431, TIC 31374837), Astrophysics - Earth and Planetary Astrophysics
Abstract: We present the bright (V$_{mag} = 9.12$), multi-planet system TOI-431, characterised with photometry and radial velocities. We estimate the stellar rotation period to be $30.5 \pm 0.7$ days using archival photometry and radial velocities. TOI-431b is a super-Earth with a period of 0.49 days, a radius of 1.28 $\pm$ 0.04 R$_{\oplus}$, a mass of $3.07 \pm 0.35$ M$_{\oplus}$, and a density of $8.0 \pm 1.0$ g cm$^{-3}$; TOI-431d is a sub-Neptune with a period of 12.46 days, a radius of $3.29 \pm 0.09$ R$_{\oplus}$, a mass of $9.90^{+1.53}_{-1.49}$ M$_{\oplus}$, and a density of $1.36 \pm 0.25$ g cm$^{-3}$. We find a third planet, TOI-431c, in the HARPS radial velocity data, but it is not seen to transit in the TESS light curves. It has an $M \sin i$ of $2.83^{+0.41}_{-0.34}$ M$_{\oplus}$, and a period of 4.85 days. TOI-431d likely has an extended atmosphere and is one of the most well-suited TESS discoveries for atmospheric characterisation, while the super-Earth TOI-431b may be a stripped core. These planets straddle the radius gap, presenting an interesting case-study for atmospheric evolution, and TOI-431b is a prime TESS discovery for the study of rocky planet phase curves., Comment: 21 pages, 11 figures, 3 appendices, accepted for publication in MNRAS
Published: 2021

35. Silicate melt inclusions in the new millennium: A review of recommended practices for preparation, analysis, and data presentation

Author: M. E. Newcombe, D. J. Rasmussen, Alexander R. L. Nichols, Matthew Jones, Oded Navon, Graham D. Layne, M. Myers, Horst R. Marschall, C. M. Allison, A. Lorenzo-Merino, K. Shimizu, Federica Schiavi, Mark D. Kurz, A. Daly, Ping-Ping Liu, A. Barth, Margaret E. Hartley, Nivea Magalhães, Yuxu Zhang, Roger L. Nielsen, Terry Plank, Janne M. Koornneef, Alexander A. Iveson, K.-Y. Lin, M. Laubier, T. Zhou, Charlotte L. DeVitre, Jordan Tucker, Glenn A. Gaetani, Yves Moussallam, M. Gaborieau, Masataka Kawaguchi, N. Luciani, Nobumichi Shimizu, Ayla S. Pamukcu, T. Kagoshima, Elizabeth Cottrell, A. Castillejo, J. Andrys, Robert J. Bodnar, Ery C. Hughes, B. Chilson-Parks, D. Butters, J. Roberge, M. Cole, Anne-Sophie Bouvier, M. Muth, Yaron Katzir, Emma Gatti, B.R. Choudhary, Felix S. Genske, Diego Narváez, A. H. Lerner, Mélissa J. Drignon, Jay B. Thomas, C. Waelkens, L. Moore, G. T. Thompson, Gokce Ustunisik, Tatsuhiko Kawamoto, B. D. Monteleone, E Johnson, A.J.J. Bracco Gartner, Katherine A. Kelley, Michael O. Garcia, D. M. Schwartz, Nicolas Cluzel, Paul J. Wallace, C.A. Angeles de la Torre, Leonid V. Danyushevsky, Estelle Rose-Koga, Peter J. Michael, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut des sciences de la terre [Lausanne] (ISTE), Université de Lausanne (UNIL), Woods Hole Oceanographic Institution (WHOI), Department of Earth Sciences [Eugene OR], University of Oregon [Eugene], Cornell University [New York], Graduate School of Oceanography [Narragansett], University of Rhode Island (URI), Instituto Politecnico Nacional [Mexico] (IPN), Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Department of Geosciences [Blacksburg], Virginia Tech [Blacksburg], Vrije Universiteit Amsterdam [Amsterdam] (VU), School of Earth Sciences [Bristol], University of Bristol [Bristol], Brown University, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, University of Connecticut (UCONN), New Mexico State University, Smithsonian Institution, School of Earth Sciences [Hobart], University of Tasmania [Hobart, Australia] (UTAS), College of Earth, Ocean and Atmospheric Sciences [Corvallis] (CEOAS), Oregon State University (OSU), Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics [Mānoa], University of Hawai‘i [Mānoa] (UHM), California Institute of Technology (CALTECH), Westfälische Wilhelms-Universität Münster (WWU), University of Manchester [Manchester], Department of Earth Sciences [Durham], Durham University, The University of Tokyo (UTokyo), Ben-Gurion University of the Negev (BGU), Kumamoto University, University of Shizuoka, Memorial University of Newfoundland [St. John's], University of Delaware [Newark], School of Earth and Space Sciences [Beijing], Peking University [Beijing], Instituto de Geofisica [Mexico], Universidad Nacional Autónoma de México (UNAM), University of Maryland [College Park], University of Maryland System, University of Toronto, Goethe-Universität Frankfurt am Main, University of Tulsa, Department of Earth Sciences [MSU Bozeman], Montana State University (MSU), Departamento de Geologia [Quito], Escuela Politécnica Nacional (EPN), The Hebrew University of Jerusalem (HUJ), University of Canterbury [Christchurch], South Dakota School of Mines and Technology (SDSM&T), American Museum of Natural History (AMNH), Boise State University, Carnegie Institution for Science [Washington], Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Syracuse University, McGill University = Université McGill [Montréal, Canada], CAS Institute of Oceanology (IOCAS), Chinese Academy of Sciences [Beijing] (CAS), China University of Petroleum, ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Université de Lausanne = University of Lausanne (UNIL), Westfälische Wilhelms-Universität Münster = University of Münster (WWU), Memorial University of Newfoundland = Université Memorial de Terre-Neuve [St. John's, Canada] (MUN), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Carnegie Institution for Science, and Geology and Geochemistry
Subjects: 010504 meteorology & atmospheric sciences, [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography, Library science, Geology, SDG 10 - Reduced Inequalities, 010502 geochemistry & geophysics, 01 natural sciences, Geochemistry and Petrology, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, In situ analysis, Data presentation, Inclusion (mineral), 0105 earth and related environmental sciences, Melt inclusions
Abstract: Mineral-hosted melt inclusions have become an important source of information on magmatic processes. As the number of melt inclusion studies increases, so does the need to establish recommended practice guidelines for collecting and reporting melt inclusion data. These guidelines are intended to ensure certain quality criteria are met and to achieve consistency among published melt inclusion data in order to maximize their utility in the future. Indeed, with the improvement of analytical techniques, new processes affecting melt inclusions are identified. It is thus critical to be able to reprocess any previously published data, such that reporting the raw data is one of the first “recommended practices” for authors and a publication-criteria that reviewers should be sensitive to. Our guidelines start with melt inclusion selection, which is a critical first step, and then continue on to melt inclusion preparation and analysis, covering the entire field of methods applicable to melt inclusions. Dedication In March of 2000, a melt inclusion workshop was held at the Chateau de Sassenage in Grenoble and a companion issue of Chemical Geology entitled “Melt Inclusions at the Millennium” was published. Erik Hauri was heavily involved with the meeting and contributed two landmark papers to the topical issue of Chemical Geology on the use of secondary ion mass spectrometry to analyze volatiles in melt inclusions. When the melt inclusion community re-convened at Woods Hole Oceanographic Institution (WHOI) in August of 2018, we were saddened that Erik was unable to join us due to his failing health. Less than a month later came the devastating news of his passing at only 52 years of age. In recognition of his incredible contributions to science in general and to the in situ analysis of melt inclusions in particular, the participants and organizers of the WHOI melt inclusion workshop dedicate this collegial paper to Erik Hauri, our colleague, mentor and friend. Thank you Erik.
Published: 2021

36. Spectro-thermometry of M dwarfs and their candidate planets: Too hot, too cool, or just right?

Author: Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii, 1680 East-West Road, Honolulu, HI 96822 (United States)]
Published: 2013
Full Text: View/download PDF

37. The nucleation and rupture process of the 1981 Gulf of Corinth earthquakes from deconvolved broad-band data

Author: Paul W. Burton, Ian Main, R. E. Abercrombie, A. Douglas, Boston University [Boston] (BU), Department of Geology and Geophysics [Edinburgh], University of Edinburgh, Ministry of Defence, School of Environmental Sciences [Norwich], University of East Anglia [Norwich] (UEA), and Department of Geology and Geophysics
Subjects: geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Nucleation, body waves, Broad band, Slip (materials science), Fault (geology), rupture and nucleation, 010502 geochemistry & geophysics, 01 natural sciences, Stress drop, Geophysics, Geochemistry and Petrology, earthquake, 2-D model, Waveform, Aegean, Seismogram, Source model, Geology, Seismology, 0105 earth and related environmental sciences
Abstract: International audience; Source parameters of the largest three normal faulting earthquakes (Ms6.6, 6.3, 6.4), in the 1981 Gulf of Corinth (Greece) sequence are determined using deconvolved broad-band data (recorded by arrays and single stations) and a 2-D finite source model. Such a model enables the spatial extent, rupture velocity and stress drop of the earthquakes t o be determined and geological observations of surface slip can be included as a further constraint on the waveform modelling. All three earthquakes were shallow (
Published: 1995

38. A model intercomparison of Titan's climate and low-latitude environment

Author: Jan Vatant d'Ollone, Tetsuya Tokano, Ralph D. Lorenz, Sébastien Lebonnois, Juan M. Lora, Department of Geology and Geophysics, Yale University, Yale University [New Haven], Institut für Geophysik und Meteorologie [Köln], Universität zu Köln, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Département des Géosciences - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Johns Hopkins University (JHU)
Subjects: Low latitude, 010504 meteorology & atmospheric sciences, Astronomy and Astrophysics, Zonal and meridional, Atmospheric sciences, 01 natural sciences, Methane, Latitude, Atmosphere, Boundary layer, chemistry.chemical_compound, symbols.namesake, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, chemistry, 13. Climate action, Space and Planetary Science, General Circulation Model, 0103 physical sciences, symbols, Environmental science, Titan (rocket family), 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Cassini-Huygens provided a wealth of data with which to constrain numerical models of Titan. Such models have been employed over the last decade to investigate various aspects of Titan's atmosphere and climate, and several three-dimensional general circulation models (GCMs) now exist that simulate Titan with a high degree of fidelity. However, substantial uncertainties persist, and at the same time no dedicated intercomparisons have assessed the degree to which these models agree with each other or the observations. To address this gap, and motivated by the proposed Dragonfly Titan lander mission, we directly compare three Titan GCMs to each other and to in situ observations, and also provide multi-model expectations for the low-latitude environment during the early northern winter season. Globally, the models qualitatively agree in their representation of the atmospheric structure and circulation, though one model severely underestimates meridional temperature gradients and zonal winds. We find that, at low latitudes, simulated and observed atmospheric temperatures closely agree in all cases, while the measured winds above the boundary layer are only quantitatively matched by one model. Nevertheless, the models simulate similar near-surface winds, and all indicate these are weak. Likewise, temperatures and methane content at low latitudes are similar between models, with some differences that are largely attributable to modeling assumptions. All models predict environments that closely resemble that encountered by the Huygens probe, including little or no precipitation at low latitudes during northern winter. The most significant differences concern the methane cycle, though the models are least comparable in this area and substantial uncertainties remain. We suggest that, while the overall low-latitude environment on Titan at this season is now fairly well constrained, future in situ measurements and monitoring will transform our understanding of regional and temporal variability, atmosphere-surface coupling, Titan's methane cycle, and modeling thereof.
Published: 2019

39. A Positive Iris Feedback: Insights from Climate Simulations with Temperature-Sensitive Cloud–Rain Conversion

Author: Ryan Li, Alexey V. Fedorov, Trude Storelvmo, Yong-Sang Choi, Department of Geology and Geophysics [New Haven], Yale University [New Haven], University of Oslo (UiO), Océan et variabilité du climat (VARCLIM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), EWHA Womans University (EWHA), European Project: 8758005(1987), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, business.industry, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Cloud computing, 010502 geochemistry & geophysics, 01 natural sciences, chemistry.chemical_compound, chemistry, [SDU]Sciences of the Universe [physics], 13. Climate action, Climatology, Carbon dioxide, Environmental science, Climate sensitivity, IRIS (biosensor), Temperature sensitive, Climate model, Current (fluid), business, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Estimates for equilibrium climate sensitivity from current climate models continue to exhibit a large spread, from 2.1 to 4.7 K per carbon dioxide doubling. Recent studies have found that the treatment of precipitation efficiency in deep convective clouds—specifically the conversion rate from cloud condensate to rain Cp—may contribute to the large intermodel spread. It is common for convective parameterization in climate models to carry a constant Cp, although its values are model and resolution dependent. In this study, we investigate how introducing a potential iris feedback, the cloud–climate feedback introduced by parameterizing Cp to increase with surface temperature, affects future climate simulations within a slab ocean configuration of the Community Earth System Model. Progressively stronger dependencies of Cp on temperature unexpectedly increase the equilibrium climate sensitivity monotonically from 3.8 to up to 4.6 K. This positive iris feedback puzzle, in which a reduction in cirrus clouds increases surface temperature, is attributed to changes in the opacity of convectively detrained cirrus. Cirrus clouds reduced largely in ice content and marginally in horizontal coverage, and thus the positive shortwave cloud radiative feedback dominates. The sign of the iris feedback is robust across different cloud macrophysics schemes, which control horizontal cloud cover associated with detrained ice. These results suggest a potentially strong but highly uncertain connection among convective precipitation, detrained anvil cirrus, and the high cloud feedback in a climate forced by increased atmospheric carbon dioxide concentrations. Supplemental information related to this paper is available at the Journals Online website: https://doi.org/10.1175/JCLI-D-18-0845.s1. © 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
Published: 2019

40. Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu—A spinning top–shaped rubble pile

Author: Paul A. Abell, Eri Tatsumi, Makoto Yoshikawa, Yoshiaki Ishihara, Tomohiro Yamaguchi, Manabu Yamada, Go Ono, Moe Matsuoka, Yuto Takei, Yoshiyuki Tsuda, Sei-ichiro Watanabe, J. P. Bibring, Y. Yokota, Satoshi Tanaka, Kent Yoshikawa, Rina Noguchi, Kohei Kitazato, Goro Komatsu, Koji Wada, Yuri Shimaki, Masaki Fujimoto, Atsushi Fujii, Osamu Mori, Shota Kikuchi, Takahiro Iwata, Takanobu Shimada, H. Ikeda, Masahiko Arakawa, Noriyuki Namiki, Shingo Kameda, Na. Hirata, Robert Gaskell, Shogo Tachibana, Olivier S. Barnouin, T. Takahashi, Naoki Nishikawa, C. Honda, Fuyuto Terui, K. Ogawa, Masahiro Hayakawa, Chikako Hirose, Hikaru Yabuta, Naoya Sakatani, Masatoshi Hirabayashi, Daniel J. Scheeres, Yuichiro Cho, Kei Shirai, Masateru Ishiguro, Hiroshi Takeuchi, Yuya Mimasu, Christian Krause, Hideaki Miyamoto, Tomokatsu Morota, H. Suzuki, Toru Kouyama, Hirotaka Sawada, Tetsuharu Fuse, Ryodo Hemmi, Kosuke Yoshioka, Ryudo Tsukizaki, Yuichi Iijima, M. Ozaki, S. Sugita, Takanao Saiki, Tatsuaki Okada, Stefania Soldini, Ralf Jaumann, Satoru Nakazawa, Naru Hirata, Masanao Abe, Aurelie Moussi, T. M. Ho, A. S. French, Eric Palmer, Jay W. McMahon, Koji Matsumoto, Naoko Ogawa, Satoshi Hosoda, Yukio Yamamoto, T. Sugiyama, R. Honda, Tomoki Nakamura, Hiroki Senshu, Hajime Yano, Tatsuhiro Michikami, Patrick Michel, Hideaki Kikuchi, National Institute of Polar Research [Tokyo] (NiPR), Plasma Research Center, University of Tsukuba, Hiroshima University, Department of Natural History Sciences, Hokkaido University [Sapporo, Japan], Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), Institute of Ecology, Tallinn University-Tallinn University, Mitsubishi Research Institute, Inc., Graduate School of Science and Engineering, Tokyo Metropolitan University [Tokyo], Planetary Science Institute [Tucson] (PSI), Service d'hépato-gastro-entérologie [Hôpital Saint-Louis], Groupe Hospitalier Saint Louis - Lariboisière - Fernand Widal [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), IHP Microelctronics, Tsukuba Space Center (TKSC), Japan Aerospace Exploration Agency [Tokyo] (JAXA), Department of Physics, Tokyo, Waseda University, Department of Applied Physics, The University of Tokyo, Seoul National University [Seoul] (SNU), Institute for Research on Earth Evolution [Yokosuka] (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), National Institute of Advanced Industrial Science and Technology (AIST), Advanced Materials Institute and Department of Chemistry, Fukuoka University, Department of Applied Mathematics and Physics, Graduate school of Mathematics, Kyoto-Kyoyo University, Department of Environmental and Materials Engineering, Nagoya Institute, University of Electro-Communications [Tokyo] (UEC), Institute of Observational Research for Global Change, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Graduate School of Science and Technology, Keio University, ANR: 15-IDEX-0001,UCA JEDI,Idex UCA JEDI(2015), Department of Earth and Planetary Sciences [Kobe], Kobe University, Institute for Sustainable Humanosphere (RISH), Kyoto University [Kyoto], Department of Geology and Geophysics, USDA Agricultural Research Service [Maricopa, AZ] (USDA), United States Department of Agriculture (USDA), Rikkyo University [Tokyo], Graduate School of Pharmaceutical Sciences, Tohoku, Tohoku University [Sendai], Biomécanique et génie biomédical (BIM), Centre National de la Recherche Scientifique (CNRS), Department of Physics, University of California [Irvine] (UCI), University of California-University of California, University of Alaska [Fairbanks] (UAF), Information Science Laboratory, Dept. of Electronics Engineering, University of Electro-Communication, DLR Institute of Planetary Research, German Aerospace Center (DLR), University of Potsdam, Department of Electronics and Electrical Engineering, Faculty of Science and Technology, Keio University, Hokkaido Information University, Université de Tsukuba = University of Tsukuba, Tallinn University, Tokyo Metropolitan University [Tokyo] (TMU), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Colorado [Boulder], Central Research Institute of Electrical Power Industry, Department of Physics [Tokyo], Department of Applied Physics, University of Fukui, University of Fukui, Tokyo Institute of Technology [Tokyo] (TITECH), and ANR-15-IDEX-0001,UCA JEDI,Idex UCA JEDI(2015)
Subjects: Multidisciplinary, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Rubble, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Geometry, engineering.material, 01 natural sciences, Asteroid, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Homogeneity (physics), Cubic centimetre, engineering, Sample collection, Asteroid Ryugu, Pile, 010303 astronomy & astrophysics, Spinning, Slope stability analysis, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Hayabusa2
Abstract: 著者人数: 60名 (所属. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS): 渡邊, 誠一郎; 野口, 里奈; 嶌生, 有理; 吉川, 真; 菊地, 翔太; 橘, 省吾; 石原, 吉明; 坂谷, 尚哉; 竹内, 央; 岡田, 達明; 安部, 正真; 山本, 幸生; 田中, 智; 白井, 慶; 松岡, 萌; 横田, 康弘; 山口, 智宏; 尾川, 順子; 三桝, 裕也; 高橋, 忠輝; 竹井, 洋; 藤井, 淳; 岩田, 隆浩; 早川, 雅彦; 細田, 聡史; 森, 治; 澤田, 弘崇; 嶋田, 貴信; Soldini, Stefania; 矢野, 創; 月崎, 竜童; 尾崎, 正伸; 飯島, 祐一; 藤本, 正樹; 照井, 冬人; 佐伯, 孝尚; 中澤, 暁; 津田, 雄一), Accepted: 2019-03-07, 資料番号: SA1180386000
Published: 2019

41. Miocene fire intensification linked to continuous aridification on the Tibetan Plateau

Author: Qingquan Meng, Xiaoli Yan, Fuli Wu, Pilong Shi, Yunfa Miao, Gilles Escarguel, Chunhui Song, Yibo Yang, Haijian Lu, Sophie Warny, Xiaomin Fang, Bihong Fu, Northwest Institute of Eco-Environment and Resources, University of Chinese Academy of Sciences, University of Chinese Academy of Sciences-University of Chinese Academy of Sciences, Key Laboratory of Continental Collision and Plateau Uplift, Chinese Academy of Sciences [Changchun Branch] (CAS)-Institute of Tibetan Plateau Research, Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA, Louisiana State University (LSU), Institute of Geology [Beijing], Chinese Academy of Geological Sciences [Beijing] (CAGS), Ministry of Land and Resources (MLR)-Ministry of Land and Resources (MLR), Institute of Remote Sensing and Digital Earth (RADI), Chinese Academy of Sciences [Beijing] (CAS), School of Earth Science & Key Laboratory of Mineral Resources in Western China, Lanzhou University, Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)
Subjects: 010506 paleontology, geography, Plateau, geography.geographical_feature_category, Geology, 15. Life on land, 010502 geochemistry & geophysics, 01 natural sciences, Paleontology, 13. Climate action, Aridification, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, 0105 earth and related environmental sciences
Abstract: International audience; Although fire is considered an importantfactor in global vegetation evolution and cli- mate change, few high-resolution Miocene fire records have been obtained worldwide. Here, two independent micro-charcoal–based fire records from the northern Tibetan Plateau were analyzed; both show similar trends in micro- charcoal concentrations through time, with low abundances in the warmer Middle Miocene Climate Optimum (18–14 Ma) followed by a continuous increase throughout the late Mio- cene (14–5 Ma) cooling. Our detailed statistical analyses show that the micro-charcoal concen- tration trend is highly positively correlated to the trend in oxygen isotopes (δ18O, r = 0.94) and xerophytic species (%Xero, r = 0.95). We propose that the intensified fire frequency on the Tibetan Plateau mainly originated from the forest-steppe ecotone as a result of the continuous aridifica- tion in winter driven by the global cooling and decreased atmospheric pCO2 that occurred dur- ing 18–5 Ma, with a secondary control by the tectonic activity of the northern Tibetan Plateau.
Published: 2019

42. Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador)

Author: Jennifer M Garrison, Axel K. Schmitt, Bodo Weber, Julie Schindlbeck-Belo, A. Cisneros de León, Steffen Kutterolf, Kuo-Lung Wang, Kenneth W.W. Sims, Hao-Yang Lee, Robert B. Trumbull, Walter Hernández, Lisa Kant, Schmitt, A. K., 1 Institut für Geowissenschaften Universität Heidelberg Heidelberg Germany, Kutterolf, S., 2 GEOMAR Helmholtz Centre for Ocean Research Kiel SFB574 Kiel Germany, Schindlbeck‐Belo, J. C., Hernández, W., 3 Observatorio Ambiental Ministerio de Medio Ambiente y Recursos Naturales San Salvador El Salvador, Sims, K. W. W., 4 Department of Geology and Geophysics University of Wyoming Laramie WY USA, Garrison, J., 5 Department of Geosciences and Environment California State University Los Angeles CA USA, Kant, L. B., Weber, B., 6 Departamento de Geología Centro de Investigación Científica y de Educación Superior de Ensenada Ensenada BC Mexico, Wang, K.‐L., 7 Institute of Earth Sciences Academia Sinica Taipei Taiwan, Lee, H.‐Y., Trumbull, R. B., and 9 GFZ German Research Centre for Geosciences Potsdam Germany
Subjects: Zircon, 010504 meteorology & atmospheric sciences, Geothermobarometry, 551.701, Geochemistry, Silicic, Central America, 010502 geochemistry & geophysics, 01 natural sciences, Geophysics, Geochemistry and Petrology, Oxygen isotopes, Rhyolite, Geochronology, Magma, Caldera, U‐series, Igneous differentiation, SIMS, Geology, 0105 earth and related environmental sciences
Abstract: The Tierra Blanca (TB) eruptive suite comprises the last four major eruptions of Ilopango caldera in El Salvador (≤45 ka), including the youngest Tierra Blanca Joven eruption (TBJ; ∼106 km3): the most voluminous event during the Holocene in Central America. Despite the protracted and productive history of explosive silicic eruptions at Ilopango caldera, many aspects regarding the longevity and the prevailing physicochemical conditions of the underlying magmatic system remain unknown. Zircon 238U‐230Th geochronology of the TB suite (TBJ, TB2, TB3, and TB4) reveals a continuous and overlapping crystallization history among individual eruptions, suggesting persistent melt presence in thermally and compositionally distinct magma reservoirs over the last ca. 80 kyr. The longevity of zircon is in contrast to previously determined crystallization timescales of, Plain Language Summary: The collapse of a volcano edifice into its shallow magma chamber can produce one of the most dangerous single events in nature, known as a caldera‐forming eruption. The TBJ eruption in El Salvador is of this kind and occurred around 1,500 years ago, having a profound impact on Maya societies. Because of this, it is crucial to understand the inner workings of caldera‐forming eruptions to assess volcanic risks and their mitigation. Beneath Ilopango caldera, the micrometer‐sized radioisotopically datable mineral zircon grew within different storage levels of a silica‐rich magma reservoir suggesting continuous melt presence for up to ca. 80,000 years prior to eruption. The time information given by zircon contrasts with that extracted from other, more abundant minerals from the same rocks (, Key Points: U‐Th zircon ages for the last four explosive eruptions of Ilopango caldera reveal a long‐lived magma reservoir (>80 kyr). Contrasting residence times for major minerals and zircon suggest extraction of zircon along with evolved melt from crystal residue. Melt extraction from vertically extensive, thermally zoned magma reservoir., Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
Published: 2021

43. The seesaw response of the Intertropical and South Pacific convergence zones to hemispherically asymmetric thermal forcing

Author: Bowen Zhao, Alexey V. Fedorov, Department of Geology and Geophysics [New Haven], Yale University [New Haven], Océan et variabilité du climat (VARCLIM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Intertropical Convergence Zone, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Forcing (mathematics), Radiative forcing, 010502 geochemistry & geophysics, Convergence zone, Rainband, 01 natural sciences, Seesaw molecular geometry, 13. Climate action, Climatology, Thermal, Convergence (routing), Climate model, Precipitation, ComputingMilieux_MISCELLANEOUS, Geology, 0105 earth and related environmental sciences
Abstract: Considerations based on atmospheric energetics and aqua-planet model simulations link the latitudinal position of the global intertropical convergence zone (ITCZ) to atmospheric cross-equatorial energy transport—a greater southward transport corresponds to a more northerly position of the ITCZ. This study, rather than concentrating of the zonally-averaged ITCZ, focuses on the tropical Pacific and looks separately at precipitation in the northern and southern hemispheres. Using numerical experiments, we show that in the tropical Pacific the response of the fully coupled ocean-atmosphere system to a hemispherically asymmetric thermal forcing, modulating atmospheric cross-equatorial energy transport, involves an interplay between the ITCZ and its counterpart in the South Pacific—the Southern Pacific convergence zone (SPCZ). This interplay leads to interhemispheric seesaw changes in tropical precipitation, such that the latitudinal position of each rain band remains largely fixed, but their intensities follow a robust inverse relationship. The seesaw behavior is also evident in the past and future coupled climate simulations of the Climate Model Intercomparison Project Phase 5 (CMIP5). We further show that the tropical Pacific precipitation response to thermal forcing is qualitatively different between the aquaplanet (without ocean heat transport), slab-ocean (with climatological ocean heat transport represented by a “Q-flux”) and fully-coupled model configurations. Specifically, the induced changes in the ITCZ latitudinal position successively decrease, while the seesaw precipitation intensity response becomes more prominent, from the aqua-planet to the slab-ocean to the fully-coupled configuration. The ITCZ/SPCZ seesaw can explain a precipitation dipole pattern observed in paleoclimate without invoking a too strong climate forcing and is relevant to future projections of tropical precipitation.
Published: 2021

44. NARROW-K-BAND OBSERVATIONS OF THE GJ 1214 SYSTEM

Author: Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)]
Published: 2013
Full Text: View/download PDF

45. CANDIDATE PLANETS IN THE HABITABLE ZONES OF KEPLER STARS

Author: Gaidos, Eric [Department of Geology and Geophysics, University of Hawai'i at Manoa, Honolulu, HI 96822 (United States)]
Published: 2013
Full Text: View/download PDF

46. A SPECTROSCOPIC CATALOG OF THE BRIGHTEST (J < 9) M DWARFS IN THE NORTHERN SKY{sup ,}

Author: Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii, 1680 East-West Road, Honolulu, HI 96822 (United States)]
Published: 2013
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47. The role of herding strategies in the exploitation of natural resources by early mining communities in the Caucasus

Author: Rémi Berthon, Julia Giblin, Marie Balasse, Eric Bellefroid, Denis Fiorillo, Archéozoologie, archéobotanique : sociétés, pratiques et environnements (AASPE), Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN), Quinnipiac University, Department of Geology and Geophysics, Yale University, Yale University [New Haven], and ANR-12-FRAL-0002,MINES,Du sel, du cuivre et de l'or : origines et développement des industries minières au Caucase(2012)
Subjects: 010506 paleontology, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, 060102 archaeology, Natural resource economics, 0601 history and archaeology, 06 humanities and the arts, Herding, Business, 01 natural sciences, ComputingMilieux_MISCELLANEOUS, Exploitation of natural resources, 0105 earth and related environmental sciences
Abstract: International audience
Published: 2021

48. CLIMATE INSTABILITY ON TIDALLY LOCKED EXOPLANETS

Author: Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)]
Published: 2011
Full Text: View/download PDF

49. AN ALL-SKY CATALOG OF BRIGHT M DWARFS

Author: Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii, 1680 East-West Road, Honolulu, HI 96822 (United States)]
Published: 2011
Full Text: View/download PDF

50. MANTLE CONVECTION, PLATE TECTONICS, AND VOLCANISM ON HOT EXO-EARTHS

Author: Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)]
Published: 2011
Full Text: View/download PDF

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