Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland
The subglacial Grímsvötn central volcano, lying within a volcanic zone directly above the core of the Iceland mantle plume, is one of the most active in Iceland. Local, regional and teleseismic earthquake data recorded on a temporary seismometer array across western Vatnajökull icecap during the sum...
Published in: | Geophysical Journal International |
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2007
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ftucambridgeesc:oai:eprints.esc.cam.ac.uk:96 2023-05-15T16:47:29+02:00 Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland Alfaro, R. Brandsdóttir, B. Rowlands, D. P. White, R. S. Gudmundsson, M. T. 2007 application/pdf http://eprints.esc.cam.ac.uk/96/ http://eprints.esc.cam.ac.uk/96/1/Alfaro,_Brandsdottir,_Rowlands,_White,_Gudmundsson_GeophyJ_Int.168%282007%29.pdf https://doi.org/10.1111/j.1365-246X.2006.03238.x en eng http://eprints.esc.cam.ac.uk/96/1/Alfaro,_Brandsdottir,_Rowlands,_White,_Gudmundsson_GeophyJ_Int.168%282007%29.pdf Alfaro, R. and Brandsdóttir, B. and Rowlands, D. P. and White, R. S. and Gudmundsson, M. T. (2007) Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland. Geophysical Journal International, 168. 863–876, doi:10.1111/j.1365-246X.2006.03238.x. DOI https://doi.org/10.1111/j.1365-246X.2006.03238.x <https://doi.org/10.1111/j.1365-246X.2006.03238.x> 02 - Geodynamics Geophysics and Tectonics Article PeerReviewed 2007 ftucambridgeesc https://doi.org/10.1111/j.1365-246X.2006.03238.x 2020-08-27T18:08:22Z The subglacial Grímsvötn central volcano, lying within a volcanic zone directly above the core of the Iceland mantle plume, is one of the most active in Iceland. Local, regional and teleseismic earthquake data recorded on a temporary seismometer array across western Vatnajökull icecap during the summer of 1998 have provided a three-dimensional image of the shallow crustal structure of the volcano. Microearthquake activity at depths of 1-4 km along the Grímsvötn caldera rim coincided with inflation of a shallow magma chamber beneath the caldera, which culminated in a 0.1 km3 eruption in December 1998. Tomographic inversion of these earthquakes define the extent of a low-velocity body beneath Grímsvötn with a volume of ~20 km3 extending to ~3 km below the surface. This low-velocity body is flanked by high velocities under the caldera rim. Delays in the P-wave arrival times through the Grímsvötn caldera from regional and teleseismic earthquakes and from two detonations ~150 km east of Grímsvötn are 0.10-0.15 s greater than the delays through the uppermost 3-4 km of crust shown by local earthquake arrivals. This suggests the presence of a further low-velocity body at depths greater than 3-4 km beneath Grímsvötn, presumed to be due to the presence of melt. Using the distribution of local seismicity and shear wave attenuation we estimate the maximum lateral extent of the region containing partial melt to be 7-8 km E-W and 4-5 km N-S. P-wave delays require a thickness of less than 1 km of pure/high percentage partial melt, assuming a sill-like magma chamber. Article in Journal/Newspaper Iceland Vatnajökull University of Cambridge, Department of Earth Sciences: ESC Publications Vatnajökull ENVELOPE(-16.823,-16.823,64.420,64.420) Geophysical Journal International 168 2 863 876 |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
02 - Geodynamics Geophysics and Tectonics |
spellingShingle |
02 - Geodynamics Geophysics and Tectonics Alfaro, R. Brandsdóttir, B. Rowlands, D. P. White, R. S. Gudmundsson, M. T. Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland |
topic_facet |
02 - Geodynamics Geophysics and Tectonics |
description |
The subglacial Grímsvötn central volcano, lying within a volcanic zone directly above the core of the Iceland mantle plume, is one of the most active in Iceland. Local, regional and teleseismic earthquake data recorded on a temporary seismometer array across western Vatnajökull icecap during the summer of 1998 have provided a three-dimensional image of the shallow crustal structure of the volcano. Microearthquake activity at depths of 1-4 km along the Grímsvötn caldera rim coincided with inflation of a shallow magma chamber beneath the caldera, which culminated in a 0.1 km3 eruption in December 1998. Tomographic inversion of these earthquakes define the extent of a low-velocity body beneath Grímsvötn with a volume of ~20 km3 extending to ~3 km below the surface. This low-velocity body is flanked by high velocities under the caldera rim. Delays in the P-wave arrival times through the Grímsvötn caldera from regional and teleseismic earthquakes and from two detonations ~150 km east of Grímsvötn are 0.10-0.15 s greater than the delays through the uppermost 3-4 km of crust shown by local earthquake arrivals. This suggests the presence of a further low-velocity body at depths greater than 3-4 km beneath Grímsvötn, presumed to be due to the presence of melt. Using the distribution of local seismicity and shear wave attenuation we estimate the maximum lateral extent of the region containing partial melt to be 7-8 km E-W and 4-5 km N-S. P-wave delays require a thickness of less than 1 km of pure/high percentage partial melt, assuming a sill-like magma chamber. |
format |
Article in Journal/Newspaper |
author |
Alfaro, R. Brandsdóttir, B. Rowlands, D. P. White, R. S. Gudmundsson, M. T. |
author_facet |
Alfaro, R. Brandsdóttir, B. Rowlands, D. P. White, R. S. Gudmundsson, M. T. |
author_sort |
Alfaro, R. |
title |
Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland |
title_short |
Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland |
title_full |
Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland |
title_fullStr |
Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland |
title_full_unstemmed |
Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland |
title_sort |
structure of the grímsvötn central volcano under the vatnajökull icecap, iceland |
publishDate |
2007 |
url |
http://eprints.esc.cam.ac.uk/96/ http://eprints.esc.cam.ac.uk/96/1/Alfaro,_Brandsdottir,_Rowlands,_White,_Gudmundsson_GeophyJ_Int.168%282007%29.pdf https://doi.org/10.1111/j.1365-246X.2006.03238.x |
long_lat |
ENVELOPE(-16.823,-16.823,64.420,64.420) |
geographic |
Vatnajökull |
geographic_facet |
Vatnajökull |
genre |
Iceland Vatnajökull |
genre_facet |
Iceland Vatnajökull |
op_relation |
http://eprints.esc.cam.ac.uk/96/1/Alfaro,_Brandsdottir,_Rowlands,_White,_Gudmundsson_GeophyJ_Int.168%282007%29.pdf Alfaro, R. and Brandsdóttir, B. and Rowlands, D. P. and White, R. S. and Gudmundsson, M. T. (2007) Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland. Geophysical Journal International, 168. 863–876, doi:10.1111/j.1365-246X.2006.03238.x. DOI https://doi.org/10.1111/j.1365-246X.2006.03238.x <https://doi.org/10.1111/j.1365-246X.2006.03238.x> |
op_doi |
https://doi.org/10.1111/j.1365-246X.2006.03238.x |
container_title |
Geophysical Journal International |
container_volume |
168 |
container_issue |
2 |
container_start_page |
863 |
op_container_end_page |
876 |
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1766037568143491072 |