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2. Paleoenvironmental insights from a middle Pennsylvanian trace-fossil assemblage during the late Paleozoic ice age in southern Brazil.

Author

Velásquez, Gabriela, Silva, Dhiego, Mottin, Thammy Ellin, de Filippis Alfaro, Lorena, and Vesely, Fernando Farias

Subjects
*GLACIAL drift, *GLACIAL Epoch, *PENNSYLVANIAN Period, *PHANEROZOIC Eon, *CLIMATE extremes, *TRACE fossils
Abstract

Trace fossils play a fundamental role as biotic records in glacial deposits associated with the Late Paleozoic Ice Age, especially in the upper units of the Itararé Group in the Paraná Basin, where they are widely described and studied. The absence of ichnological studies for the lower interval of the Itararé Group, represented by the Campo do Tenente Formation, creates a significant gap in understanding the interaction between organisms and glacial environment during the middle Pennsylvanian period in the Paraná Basin. Addressing this gap provides new insights into adaptive strategies and paleoecological aspects related to extreme climatic events. Through macro and microscopic descriptions, we documented for the first time the occurrence of eight ichnotaxa in a siltstone interval of the Campo do Tenente Formation: Dimorphicnus isp., Diplichnites gouldi, Helminthoidichnites tenuis, Hormosiroidea meandrica, Irichnus saltatorius, Merostomichnites narragansettensis, Monomorphicnus lineatus, and Umfolozia sinuosa. This trace fossil association, dominated by arthropod trackways and burrows of wormlike organisms, indicates the coexistence of the Mermia and Scoyenia ichnofacies. Combined with the sedimentological data, these results reflect marginal continental conditions of shallow and restricted environments, with occasional input of glacial freshwater. These contributions not only provide new insights into the understudied ichnological content of this interval of the Itararé Group but also offer important paleoenvironmental and paleoecological perspectives on the middle Pennsylvanian during the most significant glaciation of the Phanerozoic. • Arthropod trackways and burrows from wormlike organisms dominate a siltstone interval in the Campo do Tenente Formation. • Ichnospecies suggest Mermia and Scoyenia ichnofacies in a marginal marine setting with glacial freshwater input. • First documentation of Dimorphichnus isp. and Merostomichnites narragansettensis in the Itararé Group. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Geophysical Methods Applied to the Study of Lakes and PaleoLakes in Tierra del Fuego

Author

Prezzi, Claudia, Orgeira, María Julia, Coronato, Andrea, Onorato, María R., Quiroga, Diego, López, Ramiro, Ponce, Juan Federico, Magneres, Ignacio, Núñez Demarco, Pablo A., Perucca, Laura P., Palermo, Pedro, Litvin, Yuri, Series Editor, Jiménez-Franco, Abigail, Series Editor, Mukherjee, Soumyajit, Series Editor, Chaplina, Tatiana, Series Editor, and Acevedo, Rogelio Daniel, editor

Published
2021
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5. Geomorphology and geosystem services of the Indren-Cimalegna area (Monte Rosa massif – Western Italian Alps)

Author

Federico Tognetto, Luigi Perotti, Cristina Viani, Nicola Colombo, and Marco Giardino

Subjects
geomorphological mapping, geosystem services, glacial environment, periglacial environment, long-term ecological research, western italian alps, Maps, G3180-9980
Abstract

New strategies for preservation of geodiversity and geosystem services need to be developed for mountain areas that are vulnerable to climate change and human activities. Detailed geomorphological surveys and geosystem services analyses have been carried out in the Indren-Cimalegna area, southern slope of Monte Rosa (Western Italian Alps). From remote sensing analysis and field inventories, a geomorphological map (1:5000) was created, with a new GIS-compliant legend, targeted to the studies of glacial and periglacial environments. A geosystem services map (1:15,000) was also produced, presenting a two-fold analysis of interactions between geomorphology and human activity, showing (1) the role of distinct landforms as specific services offered to society and (2) the threats posed by morphodynamic processes to human activities. These maps are presented as tools for enhancing proper planning and management of high mountains modified by climate change and human activities within a sustainable development perspective.

Published
2021
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6. Geomorphology and geosystem services of the Indren-Cimalegna area (Monte Rosa massif - Western Italian Alps).

Author

Tognetto, Federico, Perotti, Luigi, Viani, Cristina, Colombo, Nicola, and Giardino, Marco

Subjects
*GEOMORPHOLOGY, *GEOMORPHOLOGICAL mapping, *MOUNTAIN climate, *GEODIVERSITY, *REMOTE sensing, *CLIMATE change
Abstract

New strategies for preservation of geodiversity and geosystem services need to be developed for mountain areas that are vulnerable to climate change and human activities. Detailed geomorphological surveys and geosystem services analyses have been carried out in the Indren-Cimalegna area, southern slope of Monte Rosa (Western Italian Alps). From remote sensing analysis and field inventories, a geomorphological map (1:5000) was created, with a new GIS-compliant legend, targeted to the studies of glacial and periglacial environments. A geosystem services map (1:15,000) was also produced, presenting a two-fold analysis of interactions between geomorphology and human activity, showing (1) the role of distinct landforms as specific services offered to society and (2) the threats posed by morphodynamic processes to human activities. These maps are presented as tools for enhancing proper planning and management of high mountains modified by climate change and human activities within a sustainable development perspective. [ABSTRACT FROM AUTHOR]

Published
2021
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7. Comparison of Mass Wasting Processes on the Slopes of the Rockall Trough, Northeast Atlantic

Author

Georgiopoulou, Aggeliki, Benetti, Sara, Shannon, Patrick M., Sacchetti, Fabio, Haughton, Peter D. W., Comas-Bru, Laia, Krastel, Sebastian, Krastel, Sebastian, editor, Behrmann, Jan-Hinrich, editor, Völker, David, editor, Stipp, Michael, editor, Berndt, Christian, editor, Urgeles, Roger, editor, Chaytor, Jason, editor, Huhn, Katrin, editor, Strasser, Michael, editor, and Harbitz, Carl Bonnevie, editor

Published
2014
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8. Postmortem analysis of WWI human remains from Italian glaciers in rare environmental conditions.

Author

Gaudio, Daniel, De Luca, L., Cirielli, V., Caccianiga, M., Bassi, C., Cappellozza, N., Galassi, A., Nicolis, F., and Cattaneo, C.

Subjects
*CAUSES of death, *ARCHAEOLOGY, *MILITARY personnel, *ANTHROPOLOGY, *TAPHONOMY
Abstract

The authors report the results obtained by a multidisciplinary investigation of nine cases of human remains belonging to unknown Austrian WWI soldiers found in a glacial environment in the North-Eastern Alps. The aim of this research is to investigate the biological profile, pathology and cause of death, and taphonomic details of the soldiers' bodies preserved in the glacial environment of the Alps. The human remains were recovered by forensic archeological methods. The approach to the postmortem analysis was specifically chosen on a case by case basis according to the conditions of the different corpses, which varied from advanced decomposition to skeletonization. A multidisciplinary approach was applied to the human remains, including anthropological and taphonomical analysis and, in one case, botanic investigations on the intestinal contents. Soft tissues, where present, were mainly saponified, presenting pseudo-mummified areas and only in one case were partially mummified. Trauma analysis revealed several perimortem injuries. In addition peculiar weathering such as cracking, deformations, wear and abrasions were found on the bones of these individuals. This study, by means of a multidisciplinary approach, allowed the recovery and interpretation of much information on the life and death of these men who fought in incredible and merciless conditions, and increases and implements the data provided by documents during the "White War" phase of WWI. [ABSTRACT FROM AUTHOR]

Published
2019
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9. Reconstrucción geomorfológica del último máximo glaciar en la cuenca del río San Juan, Argentina.

Author

A. P., Forte and C. D., Villarroel

Abstract

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Published
2019
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10. Vegetation change across the Drake Passage region linked to late Eocene cooling and glacial disturbance after the Eocene-Oligocene transition

Author

Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Natural Environment Research Council (UK), Thompson, Nick, Salzmann, Ulrich, López-Quirós, Adrián, Bijl, Peter K., Hoem, Frida S., Etourneau, Johan, Sicre, Marie-Alexandrine, Roignant, Sabine, Hocking, Emma, Amoo, Michael, Escutia, Carlota, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Natural Environment Research Council (UK), Thompson, Nick, Salzmann, Ulrich, López-Quirós, Adrián, Bijl, Peter K., Hoem, Frida S., Etourneau, Johan, Sicre, Marie-Alexandrine, Roignant, Sabine, Hocking, Emma, Amoo, Michael, and Escutia, Carlota

Abstract

The role and climatic impact of the opening of the Drake Passage and how it affected both marine and terrestrial environments across the Eocene-Oligocene transition (EOT ∼34 Ma) period remains poorly understood. Here we present new terrestrial palynomorph data compared with recently compiled lipid biomarker (n-alkane) data from Ocean Drilling Program (ODP) Leg 113, Site 696, drilled on the margin of the South Orkney Microcontinent (SOM) in the Weddell Sea, to investigate changes in terrestrial environments and palaeoclimate across the late Eocene and early Oligocene (∼37.6-32.2 Ma). Early late Eocene floras and sporomorph-based climate estimates reveal Nothofagus-dominated forests growing under wet temperate conditions, with mean annual temperature (MAT) and precipitation (MAP) around 12 C and 1802 mm respectively. A phase of latest Eocene terrestrial cooling at 35.5 Ma reveals a decrease in MAT by around 1.4 C possibly linked to the opening of the Powell Basin. This is followed by an increase in reworked Mesozoic sporomorphs together with sedimentological evidence indicating ice expansion to coastal and shelf areas approximately 34.1 Myr ago. However, major changes to the terrestrial vegetation at Site 696 did not take place until the early Oligocene, where there is a distinct expansion of gymnosperms and cryptogams accompanied by a rapid increase in taxon diversity and a shift in terrestrial biomarkers reflecting a change from temperate forests to cool temperate forests following 33.5 Ma. This surprising expansion of gymnosperms and cryptogams is suggested to be linked to environmental disturbance caused by repeat glacial expansion and retreat, which facilitated the proliferation of conifers and ferns. The timing of glacial onset at Site 696 is linked to the global cooling at the EOT, yet the latest Eocene regional cooling cannot directly be linked to the observed vegetation changes. Therefore, our vegetation record provides further evidence that the opening of th

Published
2022

11. Geomorphology and geosystem services of the Indren-Cimalegna area (Monte Rosa massif – Western Italian Alps)

Author

Nicola Colombo, Luigi Perotti, Federico Tognetto, Cristina Viani, and Marco Giardino

Subjects
Long-Term Ecological Research, G3180-9980, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Geomorphological mapping, Geography, Planning and Development, Climate change, Western Italian Alps, Massif, 010502 geochemistry & geophysics, 01 natural sciences, Geodiversity, Geography, geosystem services, glacial environment, Maps, periglacial environment, Earth and Planetary Sciences (miscellaneous), Physical geography, 0105 earth and related environmental sciences
Abstract

New strategies for preservation of geodiversity and geosystem services need to be developed for mountain areas that are vulnerable to climate change and human activities. Detailed geomorphological surveys and geosystem services analyses have been carried out in the Indren-Cimalegna area, southern slope of Monte Rosa (Western Italian Alps). From remote sensing analysis and field inventories, a geomorphological map (1:5000) was created, with a new GIS-compliant legend, targeted to the studies of glacial and periglacial environments. A geosystem services map (1:15,000) was also produced, presenting a two-fold analysis of interactions between geomorphology and human activity, showing (1) the role of distinct landforms as specific services offered to society and (2) the threats posed by morphodynamic processes to human activities. These maps are presented as tools for enhancing proper planning and management of high mountains modified by climate change and human activities within a sustainable development perspective.

Published
2021

12. Reconstrucción geomorfológica del último máximo glaciar en la cuenca del río San Juan, Argentina

Author

Cristian Daniel Villarroel and Ana Paula Forte

Subjects
purl.org/becyt/ford/1 [https], purl.org/becyt/ford/1.5 [https], GLACIAL GEOMORPHOLOGY, Geography, Planning and Development, CENTRAL ANDES ARGENTINA, GLACIAL ENVIRONMENT, PARAGLACIAL ENVIRONMENT, Paleontology, PLEISTOCENE GLACIATIONS, Geology, GLACIAL ACCUMULATION AND EROSION LANDFORMS, Earth-Surface Processes
Abstract

Las glaciaciones cuaternarias han dejado registro en diversos espacios geográficos de la corteza terrestre. Esto no ha sido una excepción en los Andes Centrales de Argentina y Chile, donde enormes valles labrados por la erosión glacial y depósitos morrénicos evidencian el fenómeno. Sin embargo, aún no se ha logrado establecer a nivel regional el alcance geográfico de estas glaciaciones, ni los volúmenes de agua que fueron descargados durante el retroceso de los glaciares. En éste trabajo se presenta un mapa geomorfológico de temática glacial de una región de los Andes Centrales y además se realiza por primera vez una reconstrucción geomorfológica de la zona en el momento del máximo avance glacial. Este trabajo ha sido realizado mediante el reconocimiento de las áreas ocupadas por valles en forma de U, valles asimétricos y depósitos morrénicos a partir de imágenes satelitales, fotografías aéreas y registro de geoformas en el campo. Los resultados obtenidos indican que en el área de estudio los glaciares pleistocenos llegaron a cubrir una superficie total de 582,3 km2 , es decir, un 25,5% del total del área analizada (2.085 km2). Actualmente, en dicha zona los glaciares y heleros ocupan el 3,94 % de la superficie total. Evidence of Quaternary glaciations is present in numerous places of the surface of the Earth. The Central Andes of Argentina and Chile are not the exception. Enormous “U” shaped valleys and till deposits demonstrate the widespread occurrence of this phenomenon. However, the area covered by ancient glaciers and the volume of water discharge remains poorly constrained. In this paper, we present a geomorphological map and, for the first time, a paleogeographic reconstruction of the maximum extent of glaciers during the Last Glacial Maximum. This work was carried out by surveying the area occupied by “U” shaped valleys, asymmetric valleys, and moraine deposits, using high-resolution satellite images, aerial photographs, and field data. Results show that the Pleistocene glaciers covered an area of 582.3 km2, about 25.5% of the study area (2,085 km2). Nowadays, glaciers and glacierets occupy only 3.94% of this area. Fil: Forte, Ana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina Fil: Villarroel, Cristian Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina

Published
2019

13. Cryptospores of Iapó formation: The first evidence of early land plants from Late Ordovician in Paraná Basin, Brazil.

Author

Rodrigues, Lívia C., do Carmo, Dermeval, Assine, Mario, and Steemans, Philippe

Subjects
*ACRITARCHS, *DYADS, *MARINE algae, GONDWANA (Continent)
Abstract

Assemblages of cryptospores were reported and detailed for the first time from the Upper Ordovician from Brazil. These assemblages were recovered from diamictites and shales with dropstones of the Iapó Formation, Rio Ivaí Group, Paraná Basin. The analyzed sequence represents the Hirnantian glacial deposits containing well-preserved palynomorphs with low thermal maturity and low total organic carbon. The cryptospore assemblages comprise monads, dyads, permanent tetrads, and polyads, naked or enclosed in an envelope, totalizing 17 species. The associated marine palynomorphs consist of 12 species of acritarchs and prasinophycean algae which are not discussed in detail herein. It is noticied the occurrence of Tortotubus protuberans and abundant black fragments at the lowermost portion of diamictites. The Late Ordovician cosmopolitan assemblages of cryptospores corroborate the early radiation of the land plants in western Gondwana. These results contribute to a better knowledge of Late Ordovician in Brazil and more generally in South America. • Evidence of early land plants from the glacial environment in South America. • Palynomorphs of the Hirnantian, Paraná Basin, Late Ordovician of Brazil. • The cryptospores assemblage comprises the oldest evidence of early land plants in Brazil. [ABSTRACT FROM AUTHOR]

Published
2022
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14. Influence of granitoid textural parameters on sediment composition: Implications for sediment generation

Author

Caracciolo, L., Tolosana-Delgado, R., Le Pera, E., von Eynatten, H., Arribas, J., and Tarquini, S.

Subjects
*SEDIMENTS, *POLYCRYSTALS, *PARTICLE size distribution, *MECHANICAL abrasion, *GEOGRAPHIC information systems, *DATA analysis
Abstract

Abstract: The aim of this study is to determine and characterise the control exerted by parent rock texture on sand composition as a function of grain size. The sands investigated were generated from granitoid parent rocks by the Rhone, Damma and Sidelen glaciers, which drain the Aar Massif in the Central Alps (Switzerland), and were deposited in glacial and fluvio-glacial settings. Mechanical erosion, comminution (crystal breakdown and abrasion) and hydraulic sorting are the most important processes controlling the generation of sediments in this environment, whereas chemical and/or biochemical weathering plays a negligible role. By using a GIS-based Microscopic Information System (MIS), five samples from the glacier-drained portions of the Aar basement have been analysed to determine textural parameters such as modal composition, crystal size distribution and mineral interfaces (types and lengths). Petrographic data of analysed sands include traditional point counts (Gazzi-Dickinson method, minimum of 300 points) as well as textural counts to determine interface types, frequency, and polycrystallinity in phaneritic rock fragments. According to Pettijohn''s classification, grain‐size dependent compositions vary from feldspathic litharenite (0φ fraction) via lithic arkose (1φ and 2φ) to arkose (3φ and 4φ). Compositional differences among our data set were compared to modern plutoniclastic sands from the Iberian Massif (Spain) and the St. Gabriel Mts. (California, USA), which allowed us to assess the role exerted by glaciers in generating sediments. By combining data from the MIS with those from petrographic analysis, we outlined the evolution of mineral interfaces from the parent rocks to the sediments. [Copyright &y& Elsevier]

Published
2012
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16. Paraglacial gullying of sediment-mantled slopes: a case study of Colletthøgda, Kongsfjorden area, West Spitsbergen (Svalbard).

Author

Mercier, Denis, Etienne, Samuel, SeIIier, Dominique, and André, Marie-Françoise

Subjects
PERIGLACIAL processes, GEOMORPHOLOGICAL research, LANDSCAPE changes
Abstract

The article presents a case study which investigates the paraglacial gullying of sediment-mantled slopes at Colletthøgda in Kongsfjorden area in West Spitsbergen, Norway. It discusses the intensity of paraglacial processes and gully erosion using quantification of erosion and morphometric parameters. It relates that gully formation is made through rapid melting of dead-ice cores, which results to slope form modification. It notes that paraglacial evolution at the site may occur rapidly.

Published
2009
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17. Nannoplankton successions in the northern Red Sea during the last glaciation (60 to 14.5 ka BP): Reactions to climate change

Author

Legge, Heiko-Lars, Mutterlose, Jörg, Arz, Helge W., and Pätzold, Jürgen

Subjects
*CLIMATE change, *OCEANOGRAPHY, *ABSOLUTE sea level change
Abstract

Abstract: Due to its restricted connection with the Indian Ocean, the desert-enclosed Red Sea is extremely sensitive to global sea level changes and thus ideally suited for paleoceanographic studies of what occurred during the last glaciation. The understanding of its glacial history is, however, still limited. A serious obstacle to obtain satisfactory paleoecological information has been the rarity of microfossil proxy species caused by high salinities. Here, we present a continuous and well-dated calcareous nannoplankton record from the northern Red Sea, covering the interval from 60–14.5 ka BP. Our investigation shows that the composition of the calcareous nannoplankton community varied between ∼32 ka BP and 14.5 ka BP in response to rapid environmental changes which are closely correlated to climatic fluctuations described from the North Atlantic region. Heinrich events H3, H2 and H1 are dominated by Emiliania huxleyi. Gephyrocapsa oceanica and especially Gephyrocapsa ericsonii are abundant between H3–H2 and H2–H1. A less pronounced response of the calcareous nannoplankton to the high latitudinal climatic oscillations is documented prior to ∼32 ka BP, suggesting that a strong atmospheric coupling between the northern Red Sea and the North Atlantic realm was established in the late Marine Isotope Stage 3. In contrast to the previously held view of a sea level related salinity increase as the major cause for changes of the plankton communities within the glacial Red Sea, we interpret the documented variations as being caused by local hydrographic changes under the atmospheric control from the extratropics. Temperature changes and especially variations of the water stratification appear to be critical selective factors for the calcareous nannoplankton composition. [Copyright &y& Elsevier]

Published
2008
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18. Complete dynamic modeling calibration for the Thurwieser rock avalanche (Italian Central Alps)

Author

Sosio, Rosanna, Crosta, Giovanni B., and Hungr, Oldrich

Subjects
*RHEOLOGY, *ELASTICITY, *COLLOIDS, *VISCOSITY
Abstract

Abstract: Few rock avalanches have been witnessed and no exact real time description is available. The 2.5 M m3 Punta Thurwieser rock avalanche (September 2004, Italian Central Alps) is a unique event for which many quantitative observations have been gathered. This is the first case ever of a natural rock avalanche being recorded on video, and for which an almost exact value of the total time duration, from initial detachment to final deposition, is available. The landslide travelled over 2.9 km from its source partially in a glacial environment. The initial failure and the time for the complete evacuation of the source area were studied and assessed by a series of photos. The mean front velocities along the path have been estimated from the video. The final geometry and the characteristics of the deposit have been obtained by GPS measurements, aerial photos, field surveys and laboratory tests. A quasi-3D continuum dynamic analysis of the landslide motion has been performed assuming both a Voellmy and a frictional rheology in the model DAN 3D. For the first time the landslide front velocities have been used for back analyses and calibration of the rheological parameters, together with the final shape and thickness of the deposit, and its developing extension. The dynamic flow resistance parameters, initially calibrated with DAN, were adopted and validated in DAN 3D, showing good consistency. They are consistent with the existing database for calibrated landslides of similar type and scale. Flow velocities on the path segment underlain by glacial deposits (up to 55–65 m s−1) are more accurately predicted by adopting a frictional rheology (up to 50–55 m s−1) with zero pore pressure and a 26° friction angle than by a Voellmy rheology (up to 40–45 m s−1). Both observations and modelling show that glacial ice plays a substantial role in increasing the rock avalanche mobility. [Copyright &y& Elsevier]

Published
2008
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19. Re-envisioning the structure of last glacial vegetation in New Zealand using beetle fossils

Author

Burge, Philip I. and Shulmeister, James

Subjects
*FOSSILS, *POLLEN, *POLLINATION, *PLANT fertilization
Abstract

Abstract: A series of 18 fossil beetle assemblages are used to reconstruct the paleoenvironment of the northwest West Coast, New Zealand, over the period of the last interstadial–stadial transition (ca. 37,000–21,300 cal yr BP). The samples were recovered from an in-filled hollow within a dune field ca. 9 km south west of Westport (41°47′S, 171°30′E). This fossil beetle reconstruction is compared to an existing palynological reconstruction from the same site. The beetle assemblages indicate an environment of marshy shrubland interspersed with closed canopy coastal vegetation prior to glacial onset, and a mosaic of closed canopy patches and open tussock grassland during full glacial conditions. These interpretations, contrast with the palynologically based interpretation which indicates subalpine shrubland prior to glacial onset and widespread grassland with little woody vegetation during the period of maximum glacial cooling. This study is consistent with other non-pollen studies in New Zealand and indicates that the palynological interpretation of the paleoenvironment of the Westport region downplays the importance of closed canopy vegetation in the area during the transition from interstadial to full glacial (stadial) conditions. It challenges the interpretation of open vegetation at low elevations during glacial periods from pollen studies. [Copyright &y& Elsevier]

Published
2007
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20. Glacial survival of blockfields on the Varanger Peninsula, northern Norway

Author

Fjellanger, Jakob, Sørbel, Leif, Linge, Henriette, Brook, Edward J., Raisbeck, Grant M., and Yiou, Françoise

Subjects
*ICE sheets, *METAMORPHIC rocks, *GLACIAL landforms
Abstract

Abstract: For more than hundred years it has been debated whether blockfields in mountain summit areas can be used to delimit the vertical extent of Pleistocene ice sheets. In this study the relationship between blockfields, developed in quartzites and sandstones on the Varanger Peninsula, northern Norway, and glacially derived features have been evaluated. Erratics and circular ablation moraines are superimposed on the blockfields and lateral meltwater channels are eroded into them. Glacial striations and other signs of glacial sculpturing are restricted to low-lying areas with channelled ice flow. Relative ages of the blockfields and the features in them are inferred, and the first measurements of in-situ produced cosmogenic nuclides from the Varanger Peninsula are reported. We conclude that the blockfields have survived underneath at least one thick, cold-based ice sheet. Thus, these blockfields cannot be used as indicators of ice-free conditions as previously suggested for southern Norway. Our results have implications for the potential for land surface preservation beneath ice sheets and for glacial reconstructions in northern Fennoscandia. [Copyright &y& Elsevier]

Published
2006
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21. Antarctica, Scott Base and its environs.

Author

Elliott, Christine

Subjects
*AIRPORTS, *VOLCANOES, *GLACIERS, *SAND dunes
Abstract

The landscape in the vicinity of Scott Base is one of the most singular of landscapes in the already unique environment of the Ross Sea Region of Antarctica. A rich history of human endeavour together with a broad range of physical features such as volcanoes, various glacial landforms, polar beaches and the Dry Valleys with their own glaciers, sand dunes and patterned ground must make it one of the most fascinating areas on earth. This paper highlights some of the more notable of these landscape features. [ABSTRACT FROM AUTHOR]

Published
2005
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22. Global glacier volume projections under high-end climate change scenarios

Author

Sarah Shannon, Robin Smith, Andy Wiltshire, Tony Payne, Matthias Huss, Richard Betts, John Caesar, Aris Koutroulis, Darren Jones, and Stephan Harrison

Subjects
Glacial environment, 010504 meteorology & atmospheric sciences, 13. Climate action, Global warming, Temperature profile, 0207 environmental engineering, Global climate, 02 engineering and technology, 020701 environmental engineering, 01 natural sciences, 0105 earth and related environmental sciences
Abstract

The Paris agreement aims to hold global warming to well below 2 ∘C and to pursue efforts to limit it to 1.5 ∘C relative to the pre-industrial period. Recent estimates based on population growth and intended carbon emissions from participant countries suggest global warming may exceed this ambitious target. Here we present glacier volume projections for the end of this century, under a range of high-end climate change scenarios, defined as exceeding +2 ∘C global average warming relative to the pre-industrial period. Glacier volume is modelled by developing an elevation-dependent mass balance model for the Joint UK Land Environment Simulator (JULES). To do this, we modify JULES to include glaciated and unglaciated surfaces that can exist at multiple heights within a single grid box. Present-day mass balance is calibrated by tuning albedo, wind speed, precipitation, and temperature lapse rates to obtain the best agreement with observed mass balance profiles. JULES is forced with an ensemble of six Coupled Model Intercomparison Project Phase 5 (CMIP5) models, which were downscaled using the high-resolution HadGEM3-A atmosphere-only global climate model. The CMIP5 models use the RCP8.5 climate change scenario and were selected on the criteria of passing 2 ∘C global average warming during this century. The ensemble mean volume loss at the end of the century plus or minus 1 standard deviation is -64±5 % for all glaciers excluding those on the peripheral of the Antarctic ice sheet. The uncertainty in the multi-model mean is rather small and caused by the sensitivity of HadGEM3-A to the boundary conditions supplied by the CMIP5 models. The regions which lose more than 75 % of their initial volume by the end of the century are Alaska, western Canada and the US, Iceland, Scandinavia, the Russian Arctic, central Europe, Caucasus, high-mountain Asia, low latitudes, southern Andes, and New Zealand. The ensemble mean ice loss expressed in sea level equivalent contribution is 215.2±21.3 mm. The largest contributors to sea level rise are Alaska (44.6±1.1 mm), Arctic Canada north and south (34.9±3.0 mm), the Russian Arctic (33.3±4.8 mm), Greenland (20.1±4.4), high-mountain Asia (combined central Asia, South Asia east and west), (18.0±0.8 mm), southern Andes (14.4±0.1 mm), and Svalbard (17.0±4.6 mm). Including parametric uncertainty in the calibrated mass balance parameters gives an upper bound global volume loss of 281.1 mm of sea level equivalent by the end of the century. Such large ice losses will have inevitable consequences for sea level rise and for water supply in glacier-fed river systems.

Published
2019

23. Overview

Author

Cooper, Alan K., Carlson, Paul R., Reimnitz, Erk, Davies, Thomas A., editor, Bell, Trevor, editor, Cooper, Alan K., editor, Josenhans, Heiner, editor, Polyak, Leonid, editor, Solheim, Anders, editor, Stoker, Martyn S., editor, and Stravers, Jay A., editor

Published
1997
Full Text
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24. Overview

Author

Solheim, A., Davies, Thomas A., editor, Bell, Trevor, editor, Cooper, Alan K., editor, Josenhans, Heiner, editor, Polyak, Leonid, editor, Solheim, Anders, editor, Stoker, Martyn S., editor, and Stravers, Jay A., editor

Published
1997
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25. Glacial survival of blockfields on the Varanger Peninsula, northern Norway

Author

Grant M. Raisbeck, Leif Sørbel, Françoise Yiou, Henriette Linge, Edward J. Brook, Jakob Fjellanger, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Glacial environment, 010504 meteorology & atmospheric sciences, Pleistocene, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Weathering, Ice stream, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Surface exposure dating, 010502 geochemistry & geophysics, 01 natural sciences, Paleontology, Varanger Peninsula, Blockfields, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, Glacial period, Cosmogenic nuclide, Meltwater, Geomorphology, 0105 earth and related environmental sciences, Earth-Surface Processes, geography, geography.geographical_feature_category, 15. Life on land, Moraine, Ice sheet, Geology
Abstract

For more than hundred years it has been debated whether blockfields in mountain summit areas can be used to delimit the vertical extent of Pleistocene ice sheets. In this study the relationship between blockfields, developed in quartzites and sandstones on the Varanger Peninsula, northern Norway, and glacially derived features have been evaluated. Erratics and circular ablation moraines are superimposed on the blockfields and lateral meltwater channels are eroded into them. Glacial striations and other signs of glacial sculpturing are restricted to low-lying areas with channelled ice flow. Relative ages of the blockfields and the features in them are inferred, and the first measurements of in-situ produced cosmogenic nuclides from the Varanger Peninsula are reported. We conclude that the blockfields have survived underneath at least one thick, cold-based ice sheet. Thus, these blockfields cannot be used as indicators of ice-free conditions as previously suggested for southern Norway. Our results have implications for the potential for land surface preservation beneath ice sheets and for glacial reconstructions in northern Fennoscandia.

Published
2006

26. A global picture of the first abrupt climatic event occurring during the last glacial inception

Author

Capron, E., Landais, A., Chappellaz, J., Buiron, D., Fischer, H., Johnsen, S. J., Jouzel, J., Leuenberger, M., Masson-Delmotte, V., Stocker, T. F., Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), 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), Oeschger Centre for Climate Change Research (OCCR), University of Bern, IT University of Copenhagen, 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)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), 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)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-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)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and IT University of Copenhagen (ITU)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Northern Hemispheres, Glacial climate, Last glacial, Climatic variability, 530 Physics, Climatic events, glacial-interglacial cycle, Greenland, Last interglacial, interglacial, environmental change, Glacial geology, climate variation, Earth sciences, Last glacial inception, Geophysics, glacial environment, interstadial, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Climate variability, amplitude
Abstract

The orbital-scale transition from the last interglacial to glacial climate corresponds to the progressive organization of global millennial-scale climate variability. Here, we investigate the structure and the global fingerprint of the first warming event occurring during the last glacial inception, the Greenland InterStadial 25 (GIS 25). Using centennial to decadal-resolution measurements of d18O and dD in the ice together with d15N, d18O2 and CH4 in the trapped air, we show that GIS 25 does not coincide with large environmental changes at lower latitudes. Such an equivocal fingerprint questions whether GIS 25 is simply a smaller amplitude version of later rapid events or whether it reflects a more regional northern hemisphere origin for the initiation of the millennialscale climatic variability. After this ambiguous first rapid event, the onset of the global millennial-scale variability - characteristic of the last glacial period- occurs as a short (300 years) event ending GIS 25. Citation: Capron, E., A. Landais, J. Chappellaz, D. Buiron, H. Fischer, S. J. Johnsen, J. Jouzel, M. Leuenberger, V. Masson-Delmotte, and T. F. Stocker (2012), A global picture of the first abrupt climatic event occurring during the last glacial inception.

Published
2012

28. Paraglacial gullying of sediment-mantled slopes: a case study of Colletthøgda, Kongsfjorden area, West Spitsbergen (Svalbard)

Author

Dominique Sellier, Denis Mercier, Marie-Françoise André, Samuel Etienne, Littoral, Environnement, Télédétection, Géomatique (LETG - Nantes), Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), Université de Nantes (UN)-Université de Nantes (UN)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université de Brest (UBO)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géographie Physique et Environnementale (GEOLAB), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Clermont Auvergne (UCA)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Brest (UBO)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), Université de Nantes (UN)-Université de Nantes (UN), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)

Subjects
timescale, Spitsbergen, 010504 meteorology & atmospheric sciences, paraglacial geomorphology, Geography, Planning and Development, 010502 geochemistry & geophysics, 01 natural sciences, Paraglacial, glacial environment, Earth and Planetary Sciences (miscellaneous), Deglaciation, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, Geomorphology, 0105 earth and related environmental sciences, Earth-Surface Processes, geography, geography.geographical_feature_category, Sediment, Glacier, Vegetation, 15. Life on land, Debris, Moraine, Erosion, slope processes, Geology
Abstract

International audience; This paper evaluates the paraglacial evolution of a sediment-mantled slope in a polar maritime environment. The intensity of paraglacial processes is estimated through quantifi cation of erosion and dating of fi eld sectors with the help of photographic archives. Gully erosion has been estimated using morphometric parameters and by surveys of vegetation cover. The rapid melting of dead-ice cores controls gully formation. This leads to slope form modifi cation: gully profi le gradients are reduced from a mean of 35° to a mean ranging between 10° and 15°. Profi le evolution results from the collapse of glacier lateral moraine. All data (mean slope angle of individual gullies, frequency distribution of slope angles, fractional distance to the apex, gullying index, volume of debris mobilized, vertical erosion rate) tend to increase with increasing deglaciation age and the duration of paraglacial activity. Vegetation colonization is a response to stabilization of the ground surface and the drying up of the ground surface due to dead-ice melting. The full sequence of paraglacial slope adjustment (gully incision-stabilization) may occur rapidly at the study site, i.e. within two decades. Finally, a lateral morphogenic sequence is proposed showing the importance of paraglacial processes at the onset of the deglaciation.

Published
2009

29. One-to-one coupling of glacial climate variability in Greenland and Antarctica

Author

George R. Hoffmann, Silvia Becagli, Jean Jouzel, Oleg Rybak, Philippe Huybrechts, M. Kaczmarska, Astrid Lambrecht, Felix Fundel, L. Loulergue, K. Weiler, E. Castellano, Hutterli, Fernando Valero-Delgado, Mika Kohno, Fabrice Lambert, Roberto Udisti, Gunther Lawer, Elisabeth Isaksson, Hubertus Fischer, J. R. Petit, Valter Maggi, J. Beer, Heinrich Miller, Markus Leuenberger, Claude F. Boutron, M.-L. Siggaard-Andersen, Anna Wegner, Torbjörn Karlin, Thomas Blunier, Wolfgang Graf, Ilka Hamann, Patrik R Kaufmann, Margareta Hansson, Andreas Frenzel, J. M. Barnola, H. Oerter, Vania Gaspari, Urs Federer, Hanno Meyer, Sigfus J Johnsen, Robert Mulvaney, Biancamaria Narcisi, Jean-Louis Tison, Jørgen Peder Steffensen, Johannes Oerlemans, Mirko Severi, Eric W. Wolff, Grant M. Raisbeck, Olivier Cattani, U. Ruth, Diedrich Fritzsche, D. Grigoriev, Geneviève C Littot, Paolo Gabrielli, Rita Traversi, Dietmar Wagenbach, Urs Siegenthaler, Regine Röthlisberger, M. R. van den Broeke, D. Dick, Barbara Delmonte, Johannes Freitag, Frank Wilhelms, F. Marino, Jan-Gunnar Winther, Maxime Debret, Renato Spahni, S. Falourd, Jakob Schwander, Barbara Stenni, S. Kipfstuhl, Dieter Lüthi, Jérôme Chappellaz, Dominique Raynaud, Thomas F. Stocker, Dorthe Dahl-Jensen, M. Bigler, Frédéric Parrenin, Carlo Barbante, Rainer Gersonde, Valérie Masson-Delmotte, Amaelle Landais, R. S. W. van de Wal, Jochen Schmitt, Sérgio H. Faria, Institute for the Dynamics of Environmental Processes-CNR, Department of Environmental Sciences, University of Ca’ Foscari [Venice, Italy], Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), 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)-Centre National de la Recherche Scientifique (CNRS), Department of Chemistry, University of Florence (UNIFI), Swiss Federal Institute of Aquatic Science and Technology (EAWAG), Climate and Environmental Physics [Bern] (CEP), Physikalisches Institut [Bern], Universität Bern [Bern]-Universität Bern [Bern], Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), University Milano-Bicocca, Department of Bentho-pelagic processes, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Forschungszentrum fur Umwelt und Gesundheit (GSF), Helmholtz-Zentrum München (HZM), University College of London [London] (UCL), Department of Physical Geography and Quaternary Geology, Stockholm University, British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Departement Geografie, Vrije Universiteit [Brussels] (VUB), Norwegian Polar Institute, Italian National agency for new technologies, Energy and sustainable economic development [Frascati] (ENEA), Institute for Marine and Atmospheric Research [Utrecht] (IMAU), Utrecht University [Utrecht], Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Department of Geological, Environmental and Marine Sciences [Trieste], Università degli studi di Trieste, Département des Sciences de la Terre, Université Libre de Bruxelles [Bruxelles] (ULB), Institute of Environmental Physics [Heidelberg] (IUP), Universität Heidelberg [Heidelberg], Barbante, C., Barnola, J. M., Becagli, S., Beer, J., Bigler, M., Boutron, C., Blunier, T., Castellano, E., Cattani, O., Chappellaz, J., Dahl Jensen, D., Debret, M., Delmonte, B., Dick, D., Falourd, S., Faria, S., Federer, U., Fischer, H., Freitag, J., Frenzel, A., Fritzsche, D., Fundel, F., Gabrielli, P., Gaspari, V., Gersonde, R., Graf, W., Grigoriev, D., Hamann, I, Hansson, M., Hoffmann, G., Hutterli, M. A., Huybrechts, P., Isaksson, E., Johnsen, S., Jouzel, J., Kaczmarska, M., Karlin, T., Kaufmann, P., Kipfstuhl, S., Kohno, M., Lambert, F., Lambrecht, A., Landais, A., Lawer, G., Leuenberger, M., Littot, G., Loulergue, L., Lüthi, D., Maggi, V., Marino, F., Masson Delmotte, V., Meyer, H., Miller, H., Mulvaney, R., Narcisi, B., Oerlemans, J., Oerter, H., Parrenin, F., Petit, J. R., Raisbeck, G., Raynaud, D., Röthlisberger, R., Ruth, U., Rybak, O., Severi, M., Schmitt, J., Schwander, J., Siegenthaler, U., Siggaard Andersen, M. L., Spahni, R., Steffensen, J. P., Stenni, Barbara, Stocker, T. F., Tison, J. L., Traversi, R., Udisti, R., Valero Delgado, F., van den Broeke, M. R., van de Wal R. S., W, Wagenbach, D., Wegner, A., Weiler, K., Wilhelms, F., Winther, J. G., Wolff, E., Barbante, C, Barnola, J, Becagli, S, Beer, J, Bigler, M, Boutron, C, Blunier, T, Castellano, E, Cattani, O, Chappellaz, J, Dahl Jensen, D, Debret, M, Delmonte, B, Dick, D, Falourd, S, Faria, S, Federer, U, Fischer, H, Freitag, J, Frenzel, A, Fritzsche, D, Fundel, F, Gabrielli, P, Gaspari, V, Gersonde, R, Graf, W, Grigoriev, D, Hansson, M, Hoffmann, G, Hutterli, M, Huybrechts, P, Isaksson, E, Johnsen, S, Jouzel, J, Kaczmarska, M, Karlin, T, Kaufmann, P, Kipfstuhl, S, Kohno, M, Lambert, F, Lambrecht, A, Landais, A, Lawer, G, Leuenberger, M, Littot, G, Loulergue, L, Luthi, D, Maggi, V, Marino, F, Masson Delmotte, V, Meyer, H, Miller, H, Mulvaney, R, Narcisi, B, Oerlemans, J, Oerter, H, Parrenin, F, Petit, J, Raisbeck, G, Raynaud, D, Rothlisberger, R, Ruth, U, Rybak, O, Severi, M, Schmitt, J, Schwander, J, Siegenthaler, U, Siggaard Andersen, M, Spahni, R, Steffensen, J, Stenni, B, Stocker, T, Tison, J, Traversi, R, Udisti, R, Valero Delgado, F, van den Broeke, M, van de Wal, R, Wagenbach, D, Wegner, A, Weiler, K, Wilhelms, F, Winther, J, Wolff, E, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-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 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), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Swiss Federal Insitute of Aquatic Science and Technology [Dübendorf] (EAWAG), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Vrije Universiteit Brussel (VUB), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Université libre de Bruxelles (ULB), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), 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), Università degli Studi di Firenze = University of Florence (UniFI), Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), 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)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), 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)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-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)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB), Helmholtz Zentrum München = German Research Center for Environmental Health, Università degli studi di Trieste = University of Trieste, Universität Heidelberg [Heidelberg] = Heidelberg University, Niels Bohr Institute ( NBI ), Laboratoire de glaciologie et géophysique de l'environnement ( LGGE ), Observatoire des Sciences de l'Univers de Grenoble ( OSUG ), 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 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 ) -Centre National de la Recherche Scientifique ( CNRS ), University of Florence, Swiss Federal Institute of Aquatic Science and Technology ( EAWAG ), Climate and Environmental Physics [Bern], University of Bern, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] ( LSCE ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research ( AWI ), Forschungszentrum fur Umwelt und Gesundheit ( GSF ), Helmholtz-Zentrum München ( HZM ), University College of London [London] ( UCL ), British Antarctic Survey ( BAS ), Natural Environment Research Council ( NERC ), Vrije Universiteit [Brussel] ( VUB ), Italian National agency for new technologies, Energy and sustainable economic development [Frascati] ( ENEA ), Institute for Marine and Atmospheric Research Utrecht ( IMAU ), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse ( CSNSM ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Geological Environmental and Marine Sciences [Trieste], University of Trieste, Université Libre de Bruxelles [Bruxelles] ( ULB ), and Institute of Environmental Physics [Heidelberg] ( IUP )

Subjects
Glacial climate, 010504 meteorology & atmospheric sciences, Meridional overturning circulation, Greenland, ice cores, Atlantic meridional overturning circulation, ice, 010502 geochemistry & geophysics, 01 natural sciences, Arctic, Ice core, Northern and Southern hemispheres, methane, Antarctica, EPICA, Dansgaard–Oeschger events, Dansgaard–Oeschger event, Ice core studies, Multidisciplinary, geography.geographical_feature_category, European Project for Ice Coring in Antarctica, article, Future sea level, Water waves, Oceanography, climate change, priority journal, Climate state, [ SDU.STU.GL ] Sciences of the Universe [physics]/Earth Sciences/Glaciology, temperature effect, Ice cap climate, glacial environment, oceanic circulation, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, isotope, climate, Northern and Southern hemisphere, 0105 earth and related environmental sciences, geography, Temperature measurement, Glacial geology, climate variation, Ice-sheet model, Oxygen, 13. Climate action, ice core record, Abrupt climate change, Environmental science, Ice sheet, ice core
Abstract

International audience; Precise knowledge of the phase relationship between climate changes in the two hemispheres is a key for understanding the Earth's climate dynamics. For the last glacial period, ice core studies1, 2 have revealed strong coupling of the largest millennial-scale warm events in Antarctica with the longest Dansgaard–Oeschger events in Greenland3, 4, 5 through the Atlantic meridional overturning circulation6, 7, 8. It has been unclear, however, whether the shorter Dansgaard–Oeschger events have counterparts in the shorter and less prominent Antarctic temperature variations, and whether these events are linked by the same mechanism. Here we present a glacial climate record derived from an ice core from Dronning Maud Land, Antarctica, which represents South Atlantic climate at a resolution comparable with the Greenland ice core records. After methane synchronization with an ice core from North Greenland9, the oxygen isotope record from the Dronning Maud Land ice core shows a one-to-one coupling between all Antarctic warm events and Greenland Dansgaard–Oeschger events by the bipolar seesaw6. The amplitude of the Antarctic warm events is found to be linearly dependent on the duration of the concurrent stadial in the North, suggesting that they all result from a similar reduction in the meridional overturning circulation.

Published
2006

30. Complete dynamic modeling calibration for the Thurwieser rock avalanche (Italian Central Alps)

Author

Sosio, R, Crosta, G, Hungr, O, Hungr, O., CROSTA, GIOVANNI, Sosio, R, Crosta, G, Hungr, O, Hungr, O., and CROSTA, GIOVANNI

Abstract

Few rock avalanches have been witnessed and no exact real time description is available. The 2.5 M m3 Punta Thurwieser rock avalanche (September 2004, Italian Central Alps) is a unique event for which many quantitative observations have been gathered. This is the first case ever of a natural rock avalanche being recorded on video, and for which an almost exact value of the total time duration, from initial detachment to final deposition, is available. The landslide travelled over 2.9 km from its source partially in a glacial environment. The initial failure and the time for the complete evacuation of the source area were studied and assessed by a series of photos. The mean front velocities along the path have been estimated from the video. The final geometry and the characteristics of the deposit have been obtained by GPS measurements, aerial photos, field surveys and laboratory tests. A quasi-3D continuum dynamic analysis of the landslide motion has been performed assuming both a Voellmy and a frictional rheology in the model DAN 3D. For the first time the landslide front velocities have been used for back analyses and calibration of the rheological parameters, together with the final shape and thickness of the deposit, and its developing extension. The dynamic flow resistance parameters, initially calibrated with DAN, were adopted and validated in DAN 3D, showing good consistency. They are consistent with the existing database for calibrated landslides of similar type and scale. Flow velocities on the path segment underlain by glacial deposits (up to 55-65 m s- 1) are more accurately predicted by adopting a frictional rheology (up to 50-55 m s- 1) with zero pore pressure and a 26° friction angle than by a Voellmy rheology (up to 40-45 m s- 1). Both observations and modelling show that glacial ice plays a substantial role in increasing the rock avalanche mobility.

Published
2008

32. High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core

Author

Xavier Faïn, O. Pascual, Logan Mitchell, D. Baslev-Clausen, Edward J. Brook, Jean Rosen, Jérôme A Chappellaz, Daniele Romanini, James E. Lee, Thomas Blunier, Simon Schüpbach, R. Dallmayr, Christopher Stowasser, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), 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)-Centre National de la Recherche Scientifique (CNRS), Centre for Ice and Climate [Copenhagen], Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF), Archéologies, Cultures et Sociétés (ACS), Ministère de la Culture et de la Communication (MCC)-Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Climate and Environmental Physics [Bern] (CEP), Physikalisches Institut [Bern], Universität Bern [Bern]-Universität Bern [Bern], Laboratoire de glaciologie et géophysique de l'environnement ( LGGE ), Observatoire des Sciences de l'Univers de Grenoble ( OSUG ), 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 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 ) -Centre National de la Recherche Scientifique ( CNRS ), Niels Bohr Institute ( NBI ) -University of Copenhagen ( KU ), Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] ( LIPhy ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Centre National de la Recherche Scientifique ( CNRS ), Archéologies, Cultures et Sociétés ( ACS ), Ministère de la Culture et de la Communication ( MCC ) -Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Climate and Environmental Physics [Bern], University of Bern, Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-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 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)-Centre National de la Recherche Scientifique (CNRS), Oregon State University (OSU), and The publication of this article isfinanced by CNRS-INSU

Subjects
Marine isotope stage, 010504 meteorology & atmospheric sciences, 530 Physics, lcsh:Environmental protection, Stratigraphy, Greenland Ice Sheet, Greenland, 010502 geochemistry & geophysics, Atmospheric sciences, deglaciation, 01 natural sciences, Proxy (climate), Methane, spectrometry, chemistry.chemical_compound, Arctic, lcsh:Environmental pollution, Ice core, glacial environment, interstadial, lcsh:TD169-171.8, Glacial period, Stadial, Dansgaard-Oeschger cycle, lcsh:Environmental sciences, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], lcsh:GE1-350, Global and Planetary Change, Eemian, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], [ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics], Atmospheric methane, methane, Paleontology, resolution, chemistry, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, 13. Climate action, Climatology, dissolved oxygen, lcsh:TD172-193.5, ice core, Geology
Abstract

The Greenland NEEM (North Greenland Eemian Ice Drilling) operation in 2010 provided the first opportunity to combine trace-gas measurements by laser spectroscopic instruments and continuous-flow analysis along a freshly drilled ice core in a field-based setting. We present the resulting atmospheric methane (CH4) record covering the time period from 107.7 to 9.5 ka b2k (thousand years before 2000 AD). Companion discrete CH4 measurements are required to transfer the laser spectroscopic data from a relative to an absolute scale. However, even on a relative scale, the high-resolution CH4 data set significantly improves our knowledge of past atmospheric methane concentration changes. New significant sub-millennial-scale features appear during interstadials and stadials, generally associated with similar changes in water isotopic ratios of the ice, a proxy for local temperature. In addition to the midpoint of Dansgaard–Oeschger (D/O) CH4 transitions usually used for cross-dating, sharp definition of the start and end of these events brings precise depth markers (with ±20 cm uncertainty) for further cross-dating with other palaeo- or ice core records, e.g. speleothems. The method also provides an estimate of CH4 rates of change. The onsets of D/O events in the methane signal show a more rapid rate of change than their endings. The rate of CH4 increase associated with the onsets of D/O events progressively declines from 1.7 to 0.6 ppbv yr−1 in the course of marine isotope stage 3. The largest observed rate of increase takes place at the onset of D/O event #21 and reaches 2.5 ppbv yr−1.

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