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5. Low-pressure differentiation of tholeiitic lavas as recorded in segregation veins from Reykjanes (Iceland), Lanzarote (Canary Islands) and Masaya (Nicaragua)

Author

Martin, E. and Sigmarsson, O.

Subjects
Earth sciences
Abstract

Byline: E. Martin (1), O. Sigmarsson (1,2) Abstract: Segregation veins are common in lava sheets and result from internal differentiation during lava emplacement and degassing. They consist of evolved liquid, most likely replaced by gas-filter pressing from a [proportional to]50% crystallised host lava. Pairs of samples, host lavas and associated segregation veins from the Reykjanes Peninsula (Iceland), Lanzarote (Canary Islands) and the Masaya volcano (Nicaragua) show extreme mineralogical and compositional variations (MgO in host lava, segregation veins and interstitial glass ranges from 8--10 wt%, 3--6 wt%, and to less than 0.01 wt%, respectively). These samples allow the assessment of the internal lava flow differentiation mechanism, since both the parental and derived liquid are known in addition to the last magma drops in the form of late interstitial glasses. The mineralogical variation, mass-balance calculated from major- and trace element composition, and transitional metal partition between crystals and melts are all consistent with fractional crystallisation as the dominant differentiation mechanism. The interstitial glasses are highly silicic (SiO.sub.2 = 70--80 wt%) and represent a final product of high-degree (75--97%) fractional crystallisation of olivine tholeiite at a pressure close to one atmosphere. The tholeiitic liquid-line-of-decent and the composition of the residual melts are governed by the [K.sub.2][O/Na.sub.2]O of the initial basaltic magma. The granitic minimum is reached if the initial liquid has a high [K.sub.2][O/Na.sub.2]O whereas trondhjemitic composition is the final product of magma with low initial [K.sub.2][O/Na.sub.2]O. Author Affiliation: (1) Laboratoire Magmas et Volcans, OPGC - Universite Blaise Pascal -- CNRS, 5, rue Kessler, 63038, Clermont-Ferrand Cedex, France (2) Institute of Earth Sciences, University of Iceland, 101, Reykjavik, Iceland Article History: Registration Date: 14/04/2007 Received Date: 12/07/2006 Accepted Date: 13/04/2007 Online Date: 12/06/2007 Article note: Communicated by T.L. Grove. Electronic supplementary material The online version of this article (doi: 10.1007/s00410-007-0209-5) contains supplementary material, which is available to authorized users.

Published
2007

7. Trondhjemitic and granitic melts formed by tractional crystallization of an olivine tholeiite from Reykjanes Peninsula, Iceland

Author

Martin, E. and Sigmarsson, O.

Subjects
Peninsulas -- Environmental aspects, Peninsulas -- Natural history, Magma -- Environmental aspects, Earth sciences
Abstract

A pair of samples, from host lava and an included segregation vein from the Reykjanes Peninsula, Iceland, allows the assessment of a complete fractional crystallization of an olivine tholeiite at low pressure. The final product consists of silicic glasses with bimodal composition: trondhjemitic and more rarely granitic. Compilation of data on major element compositions of Icelandic silicic rocks reveals a clear difference from those of the segregation glasses. Fractional crystallization of basalts at low pressure is therefore not the most likely mechanism for the origin of silicic magmas in Iceland. Similar conclusions have been reached in studies on O- and Th-isotope compositions. On the other hand, the trondhjemitic compositions of the glasses in the segregation vein from Reykjanes Peninsula suggest that fractional crystallization of olivine tholeiites could have played a significant role during the formation of the very early continental crust. Keywords: Iceland, fractional crystallization, trondhjemite, segregation vein, interstitial glass.

Published
2005

9. Melting of a subducting oceanic crust from U-Th disequilibria in austral Andean lavas

Author

Sigmarsson, O., Martin, H., and Knowles, J.

Subjects
Ocean bottom -- Research, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

There is a uniform excess of Th, the radiogenic product of U, over U in young adakites from the Andean austral volcanic zone south of the triple junction where the Chile ridge subducts beneath South America. These adakites also show variable Th isotope ratios. It seems likely that the adakites were formed by around 20% equilibrium melting as a result of amphibole decomposition in a heterogeneous oceanic crust. Adakites may have been added to the continental crust throughout Earth's history when an ocean crust that was young and hot enough was subducted.

Published
1998

12. Uranium and 10Be enrichments by fluids in Andean arc magmas

Author

Sigmarsson, O., Condomines, M., Morris, J.D., and Harmon, R.S.

Subjects
Andes -- Natural history, Rocks, Igneous -- Composition, Volcanological research -- Chile, Magma -- Composition, Environmental issues, Science and technology, Zoology and wildlife conservation
Published
1990

16. Geothermobarometry of the 2010 Eyjafjallajökull eruption: New constraints on Icelandic magma plumbing systems

Author

Keiding, J., Sigmarsson, O., GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), Laboratoire Magmas et Volcans (LMV), 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), 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), and 4.2 Inorganic and Isotope Geochemistry, 4.0 Chemistry and Material Cycles, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum

Subjects
Eyjafjallajökull, magma chamber, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDE.MCG]Environmental Sciences/Global Changes, Iceland, 550 - Earth sciences, thermobarometry
Abstract

International audience; The 2010 Eyjafjallajökull eruption in Iceland produced mildly alkaline basalt that was emitted during the initial flank eruptive phase, whereas tephra predominately of benmorite composition was erupted during the second explosive phase from the summit of the volcano. These latter magmas show pervasive magma mingling between basalts and silicic magma. Glass and coexisting equilibrium mineral analyses have been used to define pressure-temperature crystallization paths for the eruption based on melt, clinopyroxene-melt and plagioclase-melt thermobarometry. Temperature calculations show that the early basaltic eruptions from the flank eruption have magmatic temperatures of around 1170°C (±25°C) and a narrow temperature range (

Published
2012
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17. Gliðnunarhraði Íslands metinn með aldursgreiningum á megineldstöðvum Austurlands

Author

Sigmarsson, O., Martin, Erwan, Paquette, Jean-Louis, Bosse, Valérie, Geirsson, K., Institut des Sciences de la Terre de Paris (iSTeP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and Queyroy, Marie José

Subjects
[SDU.STU] Sciences of the Universe [physics]/Earth Sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2012

20. Next article >> << Previous article Environmental pressure from the 2014–15 eruption of Bárðarbunga volcano, Iceland

Author

Gíslason, S.R, primary, Stefánsdóttir, G., additional, Pfeffer, M.A., additional, Barsotti, S., additional, Jóhannsson, Th., additional, Galeczka, I., additional, Bali, E., additional, Sigmarsson, O., additional, Stefánsson, A., additional, Keller, N.S., additional, Sigurdsson, Á., additional, Bergsson, B., additional, Galle, B., additional, Jacobo, V.C, additional, Arellano, S., additional, Aiuppa, A., additional, Jónasdóttir, E.B., additional, Eiríksdóttir, E.S., additional, Jakobsson, S., additional, Guðfinnsson, G.H., additional, Halldórsson, S.A., additional, Gunnarsson, H., additional, Haddadi, B., additional, Jónsdóttir, I., additional, Thordarson, Th., additional, Riishuus, M., additional, Högnadóttir, Th., additional, Dürig, T., additional, Pedersen, G.B.M., additional, Höskuldsson, Á., additional, and Gudmundsson, M.T., additional

Published
2015
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21. The sulfur budget of the 2011 Grimsvötn eruption, Iceland

Author

Sigmarsson, O., Haddadi, B., Carn, S., Moune, S., Gudnason, J., Yang, K.D., Clarisse, Lieven, Sigmarsson, O., Haddadi, B., Carn, S., Moune, S., Gudnason, J., Yang, K.D., and Clarisse, Lieven

Abstract

Sulfur concentrations have been measured in 28 melt inclusions (MIs) in plagioclase, clinopyroxene, and olivine crystals extracted from tephra produced during the explosive eruption of Grímsvötn in May 2011. The results are compared to sulfur concentrations in the groundmass glass in order to estimate the mass of sulfur brought to surface during the eruption. Satellite measurements yield order of magnitude lower sulfur (~0.2 Tg) in the eruption plume than estimated from the difference between MI and the groundmass glass. This sulfur "deficit" is readily explained by sulfur adhering to tephra grains but principally by sulfide globules caused by basalt-sulfide melt exsolution before degassing. A mass balance calculation reveals that approximately ~0.8 Tg of SO2 is present as globules, representing ~50% of the total sulfur budget. Most of the sulfide globules likely reside at depth due to their elevated density, for potential later remobilization by new magma or hydrothermal circulation. Key Points H2S and SO2 degassing is estimated for the 2011 eruption of Grímsvötn Satellite-based SO2 mass loading is lower than from mineral melt inclusions Half of S resides as sulfide globules; 25% enter the stratosphere ©2013. American Geophysical Union. All Rights Reserved., SCOPUS: ar.j, FLWIN, info:eu-repo/semantics/published

Published
2013

22. Formation of U-depleted rhyolite from a basanite at El Hierro, Canary Islands

Author

Sigmarsson, O., Laporte, D., Carpentier, M., Devouard, B., Devidal, J.-L., Martí Molist, Joan, Sigmarsson, O., Laporte, D., Carpentier, M., Devouard, B., Devidal, J.-L., and Martí Molist, Joan

Abstract

Phonolite and trachyte are the felsic magmas of the alkaline magma suites, which characterize the Canary Islands. The October 2011 submarine eruption off El Hierro, the westernmost island, nevertheless, produced a small volume of rhyolitic magma. The rhyolite occurred as highly vesicular, white coloured pumices enveloped in and mingled with darker coloured basanitic pumice. The basanitic pumice is relatively crystal poor with a few euhedral olivines (mostly Fo77-79), clinopyroxenes and Fe-rich spinels, whereas very rare olivine of same composition is found together with equally rare Fe-sulphide and FeTi-rich oxides in the rhyolite. The Fe-Mg exchange equilibrium in the oxides permits to calculate an equilibrium temperature of 970-890 °C for the rhyolite, in agreement with quartz-melt equilibrium at ca. 930 °C. A striking mineralogical feature of the rhyolite is the presence of rounded to contorted grains of milky quartz, which are xenocrysts incorporated and partly dissolved into the magma. Analyses of residual volatile concentrations in the glasses show that the rhyolite melt was highly degassed, whereas the basanitic glass still has important halogen concentrations. Trace element patterns of the mafic glasses and their elevated incompatible element concentrations are typical of the western Canary Island basanites. In contrast, the trace element composition of the rhyolite shows surprisingly low concentrations for all elements except the most incompatible ones (e. g. Rb, Ba, K and Th). All other measured LILE, HFSE and REE have significantly lower concentration than the basanitic counterpart that can be explained by fractionation of accessory phases (1 % apatite, 1 % sphene and 0.1 % zircon). Surprisingly, low U concentration is presumably related to elevated oxygen fugacity in the rhyolite, causing U to be in a hexavalent state, and fluxing of F-rich gas leading to volatilization of UF6, known to emanate at low temperature. The results suggest that a gas-rich basa

Published
2013

35. Dynamic magma mixing revealed by the 2010 Eyjafjallajökull eruption.

Author

Sigmarsson, O., Vlastelic, I., Andreasen, R., Bindeman, I., Devidal, J.-L., Moune, S., Keiding, J. K., Larsen, G., Höskuldsson, A., and Thordarson, Th.

Subjects
*EARTH sciences, *VOLCANIC eruptions, *MAGMAS
Abstract

The article presents a study that evaluates the triggering mechanism for the 2010 summit euption at Eyjafjallajökull volcano in South Iceland. It suggests that detailed sampling during the entire eruption was essential for deciphering the complex magmatic processes at play, namely the dynamic magma mixing. It indicates that the rapid compositional changes in the eruptive products suggest that magma mingling occurs on a timescale of few hours to days.

Published
2011
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43. Rapid shifting of a deep magmatic source at Fagradalsfjall volcano, Iceland

Author

Sæmundur A. Halldórsson, Edward W. Marshall, Alberto Caracciolo, Simon Matthews, Enikő Bali, Maja B. Rasmussen, Eemu Ranta, Jóhann Gunnarsson Robin, Guðmundur H. Guðfinnsson, Olgeir Sigmarsson, John Maclennan, Matthew G. Jackson, Martin J. Whitehouse, Heejin Jeon, Quinten H. A. van der Meer, Geoffrey K. Mibei, Maarit H. Kalliokoski, Maria M. Repczynska, Rebekka Hlín Rúnarsdóttir, Gylfi Sigurðsson, Melissa Anne Pfeffer, Samuel W. Scott, Ríkey Kjartansdóttir, Barbara I. Kleine, Clive Oppenheimer, Alessandro Aiuppa, Evgenia Ilyinskaya, Marcello Bitetto, Gaetano Giudice, Andri Stefánsson, Halldórsson, Sæmundur A [0000-0002-9311-7704], Bali, Enikő [0000-0001-7289-6393], Ranta, Eemu [0000-0003-3685-334X], Maclennan, John [0000-0001-6857-9600], Jackson, Matthew G [0000-0002-4557-6578], Whitehouse, Martin J [0000-0003-2227-577X], Scott, Samuel W [0000-0001-7608-7358], Kleine, Barbara I [0000-0002-9440-2734], Oppenheimer, Clive [0000-0003-4506-7260], Aiuppa, Alessandro [0000-0002-0254-6539], Ilyinskaya, Evgenia [0000-0002-3663-9506], Bitetto, Marcello [0000-0003-0460-9772], Giudice, Gaetano [0000-0002-9410-4139], Apollo - University of Cambridge Repository, 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), Halldorsson S.A., Marshall E.W., Caracciolo A., Matthews S., Bali E., Rasmussen M.B., Ranta E., Robin J.G., Gudfinnsson G.H., Sigmarsson O., Maclennan J., Jackson M.G., Whitehouse M.J., Jeon H., van der Meer Q.H.A., Mibei G.K., Kalliokoski M.H., Repczynska M.M., Runarsdottir R.H., Sigurdsson G., Pfeffer M.A., Scott S.W., Kjartansdottir R., Kleine B.I., Oppenheimer C., Aiuppa A., Ilyinskaya E., Bitetto M., Giudice G., and Stefansson A.

Subjects
REYKJANES PENINSULA, 3705 Geology, SOLUBILITY, 140, 128, 140/125, ERUPTION, 704/2151/431, 132, Multidisciplinary, iceland, volcanism, volatiles, Fagradalsfjall, 704/2151/213, 704/2151/598, PRESSURES, article, CONSTRAINTS, 37 Earth Sciences, EVOLUTION, 3703 Geochemistry, INSIGHTS, [SDU]Sciences of the Universe [physics], MIDOCEAN RIDGE BASALTS, OLIVINE, 704/2151/209, 3706 Geophysics, GENERATION
Abstract

Recent Icelandic rifting events have illuminated the roles of centralized crustal magma reservoirs and lateral magma transport1–4, important characteristics of mid-ocean ridge magmatism1,5. A consequence of such shallow crustal processing of magmas4,5 is the overprinting of signatures that trace the origin, evolution and transport of melts in the uppermost mantle and lowermost crust6,7. Here we present unique insights into processes occurring in this zone from integrated petrologic and geochemical studies of the 2021 Fagradalsfjall eruption on the Reykjanes Peninsula in Iceland. Geochemical analyses of basalts erupted during the first 50 days of the eruption, combined with associated gas emissions, reveal direct sourcing from a near-Moho magma storage zone. Geochemical proxies, which signify different mantle compositions and melting conditions, changed at a rate unparalleled for individual basaltic eruptions globally. Initially, the erupted lava was dominated by melts sourced from the shallowest mantle but over the following three weeks became increasingly dominated by magmas generated at a greater depth. This exceptionally rapid trend in erupted compositions provides an unprecedented temporal record of magma mixing that filters the mantle signal, consistent with processing in near-Moho melt lenses containing 107–108 m3 of basaltic magma. Exposing previously inaccessible parts of this key magma processing zone to near-real-time investigations provides new insights into the timescales and operational mode of basaltic magma systems.

Published
2022
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47. Gradual caldera collapse at Bardarbunga volcano, Iceland, regulated by lateral magma outflow

Author

Thórdís Högnadóttir, Martin Hensch, Vincent Drouin, Amy Donovan, Martin P. J. Schöpfer, Alessandro Aiuppa, Joaquín M. C. Belart, Tayo van Boeckel, Melissa Anne Pfeffer, Andrew Hooper, Sebastian Heimann, Eniko Bali, Benedikt G. Ófeigsson, Sæmundur A. Halldórsson, Gro Pedersen, Morten S. Riishuus, Stéphanie Dumont, Magnús T. Gudmundsson, Freysteinn Sigmundsson, Sigurdur Jakobsson, Olgeir Sigmarsson, Torsten Dahm, Páll Einarsson, Finnur Pálsson, Thomas R. Walter, Gunnar B. Gudmundsson, Sigrún Hreinsdóttir, Kristín Jónsdóttir, Mike Burton, Michelle Parks, Gudmundur H. Gudfinnsson, Guðfinna Aðalgeirsdóttir, Simone Cesca, Baldur Bergsson, Eoghan P. Holohan, Björn Oddsson, Matthew J. Roberts, Marco Bagnardi, Kristján Jónasson, Vala Hjörleifsdóttir, Sara Barsotti, Kristín Vogfjörd, Hildur M. Fridriksdottir, Tobias Dürig, Alexander H. Jarosch, Eyjólfur Magnússon, Karsten Spaans, Hannah I. Reynolds, School of Earth and Environment [Leeds] (SEE), University of Leeds, Department of Geology, School of Natural Sciences, Trinity College, German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), Laboratoire Magmas et Volcans (LMV), 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), University of Iceland [Reykjavik], GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), Institut des Neurosciences Cellulaires et Intégratives (INCI), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Scott Polar Research Institute, University of Cambridge [UK] (CAM), Dipartimento DiSTeM, Università degli studi di Palermo - University of Palermo, 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), Università di Palermo, Institut für Geophysik, Universität Hamburg (UHH), Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS), Gudmundsson, M., Jónsdóttir, K., Hooper, A., Holohan, E., Halldórsson, S., Ófeigsson, B., Cesca, S., Vogfjörd, K., Sigmundsson, F., Högnadóttir, T., Einarsson, P., Sigmarsson, O., Jarosch, A., Jónasson, K., Magnússon, E., Hreinsdóttir, S., Bagnardi, M., Parks, M., Hjörleifsdóttir, V., Pálsson, F., Walter, T., Schöpfer, M., Heimann, S., Reynolds, H., Dumont, S., Bali, E., Gudfinnsson, G., Dahm, T., Roberts, M., Hensch, M., Belart, J., Spaans, K., Jakobsson, S., Gudmundsson, G., Fridriksdóttir, H., Drouin, V., Dürig, T., Adalgeirsdóttir, G., Riishuus, M., Pedersen, G., Van Boeckel, T., Oddsson, B., Pfeffer, M., Barsotti, S., Bergsson, B., Donovan, A., Burton, M., Aiuppa, A., Jarðvísindastofnun (HÍ), Institute of Earth Sciences (UI), Iðnaðarverkfræði-, vélaverkfræði- og tölvunarfræðideild (HÍ), Faculty of Industrial Eng., Mechanical Eng. and Computer Science (UI), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, and University of Iceland

Subjects
Eldgos, Lateral eruption, 010504 meteorology & atmospheric sciences, Lava, Öskjugos, Hraunrennsli, 010502 geochemistry & geophysics, 01 natural sciences, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Caldera, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Multidisciplinary, Glacier Dynamics, Resurgent dome, Medicine (all), Complex volcano, Lateral Magma Flow, 16. Peace & justice, Caldera collapse, Dense-rock equivalent, Bárðarbunga, Volcano, 13. Climate action, Eruption, Magma, Geology, Seismology
Abstract

Large volcanic eruptions on Earth commonly occur with a collapse of the roof of a crustal magma reservoir, forming a caldera. Only a few such collapses occur per century, and the lack of detailed observations has obscured insight into the mechanical interplay between collapse and eruption.We usemultiparameter geophysical and geochemical data to show that the 110-square kilometer and 65-meter-deep collapse of Bárdarbunga caldera in 2014–2015 was initiated through withdrawal of magma, and lateral migration through a 48-kilometers-long dike, from a 12-kilometers deep reservoir. Interaction between the pressure exerted by the subsiding reservoir roof and the physical properties of the subsurface flow path explain the gradual, near exponential decline of both collapse rate and the intensity of the 180-day- long eruption., Civil Protection Department of the National Commissioner of the Icelandic Police. European Community’s Seventh Framework Programme grant no. 308377 (Project FUTUREVOLC). EU Seventh Framework Marie Curie project NEMOH no. 289976 CO2Volc ERC grant no. 279802, the Research Fund of the University of Iceland, the Irish Research Council, the Helmholtz Alliance on Remote Sensing and Earth System Dynamics (EDA), Bayerisches Geoinstitut through their DFG core facility for high pressure research, and UNAM/CIC Intercambio Académico.

Published
2016
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48. A dynamic mid-crustal magma domain revealed by the 2023 to 2024 Sundhnúksgígar eruptions in Iceland.

Author

Matthews SW, Caracciolo A, Bali E, Halldórsson SA, Sigmarsson O, Guðfinnsson GH, Pedersen GBM, Robin JG, Marshall EW, Aden AA, Gísladóttir BÝ, Bosq C, Auclair D, Merrill H, Levillayer N, Löw N, Rúnarsdóttir RH, Johnson SM, Steinþórsson S, and Drouin V

Abstract

Mid-crustal magma domains are the source of many basaltic eruptions. Lavas from individual eruptions are often chemically homogeneous, suggesting that they derive from single, well-mixed magma reservoirs. The 2023 to 2024 eruptions at Sundhnúksgígar in the Svartsengi volcanic system in Iceland provide an opportunity to observe the behavior of a mid-crustal magma domain at high spatial and temporal resolution by detailed sampling and geochemical characterization. We observed substantial mantle-derived geochemical variability in the products erupted in the first hours of the December 2023 and January, February, and March to May 2024 eruptions, indicating that the eruptions derived from multiple magma reservoirs, which mineral-melt equilibration pressures place in the mid crust. The unusual presence of geochemical heterogeneity in the mid-crustal magma domain provides insights into how dynamic and complex mid-crustal magma domains can be.

Published
2024
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49. Gradual caldera collapse at Bárdarbunga volcano, Iceland, regulated by lateral magma outflow.

Author

Gudmundsson MT, Jónsdóttir K, Hooper A, Holohan EP, Halldórsson SA, Ófeigsson BG, Cesca S, Vogfjörd KS, Sigmundsson F, Högnadóttir T, Einarsson P, Sigmarsson O, Jarosch AH, Jónasson K, Magnússon E, Hreinsdóttir S, Bagnardi M, Parks MM, Hjörleifsdóttir V, Pálsson F, Walter TR, Schöpfer MP, Heimann S, Reynolds HI, Dumont S, Bali E, Gudfinnsson GH, Dahm T, Roberts MJ, Hensch M, Belart JM, Spaans K, Jakobsson S, Gudmundsson GB, Fridriksdóttir HM, Drouin V, Dürig T, Aðalgeirsdóttir G, Riishuus MS, Pedersen GB, van Boeckel T, Oddsson B, Pfeffer MA, Barsotti S, Bergsson B, Donovan A, Burton MR, and Aiuppa A

Abstract

Large volcanic eruptions on Earth commonly occur with a collapse of the roof of a crustal magma reservoir, forming a caldera. Only a few such collapses occur per century, and the lack of detailed observations has obscured insight into the mechanical interplay between collapse and eruption. We use multiparameter geophysical and geochemical data to show that the 110-square-kilometer and 65-meter-deep collapse of Bárdarbunga caldera in 2014-2015 was initiated through withdrawal of magma, and lateral migration through a 48-kilometers-long dike, from a 12-kilometers deep reservoir. Interaction between the pressure exerted by the subsiding reservoir roof and the physical properties of the subsurface flow path explain the gradual, near-exponential decline of both collapse rate and the intensity of the 180-day-long eruption., (Copyright © 2016, American Association for the Advancement of Science.)

Published
2016
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