Seismicity and Pn Velocity Structure of Central West Antarctica
Abstract We have located 117 previously undetected seismic events mainly occurring between 2015 and 2017 that originated from glacial, tectonic, and volcanic processes in central West Antarctica using data recorded on Polar Earth Observing Network (POLENET/ANET) and UK Antarctic Network (UKANET) sei...
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ftdoajarticles:oai:doaj.org/article:dc78b009d54e44f5a3790c0211496072 2023-12-03T10:09:24+01:00 Seismicity and Pn Velocity Structure of Central West Antarctica Erica M. Lucas Andrew A. Nyblade Andrew J. Lloyd Richard C. Aster Douglas A. Wiens John Paul O'Donnell Graham W. Stuart Terry J. Wilson Ian W. D. Dalziel J. Paul Winberry Audrey D. Huerta 2021-02-01T00:00:00Z https://doi.org/10.1029/2020GC009471 https://doaj.org/article/dc78b009d54e44f5a3790c0211496072 EN eng Wiley https://doi.org/10.1029/2020GC009471 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2020GC009471 https://doaj.org/article/dc78b009d54e44f5a3790c0211496072 Geochemistry, Geophysics, Geosystems, Vol 22, Iss 2, Pp n/a-n/a (2021) Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.1029/2020GC009471 2023-11-05T01:35:55Z Abstract We have located 117 previously undetected seismic events mainly occurring between 2015 and 2017 that originated from glacial, tectonic, and volcanic processes in central West Antarctica using data recorded on Polar Earth Observing Network (POLENET/ANET) and UK Antarctic Network (UKANET) seismic stations. The seismic events, with local magnitudes (ML) ranging from 1.1 to 3.5, are predominantly clustered in four geographic regions; the Ellsworth Mountains, Thwaites Glacier, Pine Island Glacier, and Mount Takahe. Eighteen of the events are in the Ellsworth Mountains and can be attributed to a mixture of glacial and tectonic processes. The largest event noted in this study was a mid‐crustal (∼19 km focal depth; ML 3.5) normal mechanism earthquake beneath Thwaites Glacier. We also located 91 glacial events near the grounding zones of Thwaites Glacier and Pine Island Glacier that are predominantly associated with time periods of significant calving activity. Eight events, likely arising from volcano‐tectonic processes, occurred beneath Mount Takahe. Using Pn travel times from the seismic events, we find laterally variable uppermost mantle structure in central West Antarctica. On average, the Ellsworth Mountains are underlain by a faster mantle lid (VPn = ∼8.4 km/s) compared to the Amundsen Sea Embayment region (VPn = ∼8.1 km/s). Within the Amundsen Sea Embayment itself, we find mantle lid velocities ranging from ∼8.05 to 8.18 km/s. Laterally heterogeneous uppermost mantle structure, indicative of variable thermal and rheological structure, likely influences both geothermal heat flux and glacial isostatic adjustment spatial patterns and rates within central West Antarctica. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Pine Island Pine Island Glacier Thwaites Glacier West Antarctica Directory of Open Access Journals: DOAJ Articles Amundsen Sea Anet ENVELOPE(27.987,27.987,65.920,65.920) Antarctic Ellsworth Mountains ENVELOPE(-85.000,-85.000,-78.750,-78.750) Mount Takahe ENVELOPE(166.800,166.800,-77.217,-77.217) Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Takahe ENVELOPE(-112.233,-112.233,-76.267,-76.267) Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) West Antarctica Geochemistry, Geophysics, Geosystems 22 2 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
spellingShingle |
Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 Erica M. Lucas Andrew A. Nyblade Andrew J. Lloyd Richard C. Aster Douglas A. Wiens John Paul O'Donnell Graham W. Stuart Terry J. Wilson Ian W. D. Dalziel J. Paul Winberry Audrey D. Huerta Seismicity and Pn Velocity Structure of Central West Antarctica |
topic_facet |
Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
description |
Abstract We have located 117 previously undetected seismic events mainly occurring between 2015 and 2017 that originated from glacial, tectonic, and volcanic processes in central West Antarctica using data recorded on Polar Earth Observing Network (POLENET/ANET) and UK Antarctic Network (UKANET) seismic stations. The seismic events, with local magnitudes (ML) ranging from 1.1 to 3.5, are predominantly clustered in four geographic regions; the Ellsworth Mountains, Thwaites Glacier, Pine Island Glacier, and Mount Takahe. Eighteen of the events are in the Ellsworth Mountains and can be attributed to a mixture of glacial and tectonic processes. The largest event noted in this study was a mid‐crustal (∼19 km focal depth; ML 3.5) normal mechanism earthquake beneath Thwaites Glacier. We also located 91 glacial events near the grounding zones of Thwaites Glacier and Pine Island Glacier that are predominantly associated with time periods of significant calving activity. Eight events, likely arising from volcano‐tectonic processes, occurred beneath Mount Takahe. Using Pn travel times from the seismic events, we find laterally variable uppermost mantle structure in central West Antarctica. On average, the Ellsworth Mountains are underlain by a faster mantle lid (VPn = ∼8.4 km/s) compared to the Amundsen Sea Embayment region (VPn = ∼8.1 km/s). Within the Amundsen Sea Embayment itself, we find mantle lid velocities ranging from ∼8.05 to 8.18 km/s. Laterally heterogeneous uppermost mantle structure, indicative of variable thermal and rheological structure, likely influences both geothermal heat flux and glacial isostatic adjustment spatial patterns and rates within central West Antarctica. |
format |
Article in Journal/Newspaper |
author |
Erica M. Lucas Andrew A. Nyblade Andrew J. Lloyd Richard C. Aster Douglas A. Wiens John Paul O'Donnell Graham W. Stuart Terry J. Wilson Ian W. D. Dalziel J. Paul Winberry Audrey D. Huerta |
author_facet |
Erica M. Lucas Andrew A. Nyblade Andrew J. Lloyd Richard C. Aster Douglas A. Wiens John Paul O'Donnell Graham W. Stuart Terry J. Wilson Ian W. D. Dalziel J. Paul Winberry Audrey D. Huerta |
author_sort |
Erica M. Lucas |
title |
Seismicity and Pn Velocity Structure of Central West Antarctica |
title_short |
Seismicity and Pn Velocity Structure of Central West Antarctica |
title_full |
Seismicity and Pn Velocity Structure of Central West Antarctica |
title_fullStr |
Seismicity and Pn Velocity Structure of Central West Antarctica |
title_full_unstemmed |
Seismicity and Pn Velocity Structure of Central West Antarctica |
title_sort |
seismicity and pn velocity structure of central west antarctica |
publisher |
Wiley |
publishDate |
2021 |
url |
https://doi.org/10.1029/2020GC009471 https://doaj.org/article/dc78b009d54e44f5a3790c0211496072 |
long_lat |
ENVELOPE(27.987,27.987,65.920,65.920) ENVELOPE(-85.000,-85.000,-78.750,-78.750) ENVELOPE(166.800,166.800,-77.217,-77.217) ENVELOPE(-101.000,-101.000,-75.000,-75.000) ENVELOPE(-112.233,-112.233,-76.267,-76.267) ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Amundsen Sea Anet Antarctic Ellsworth Mountains Mount Takahe Pine Island Glacier Takahe Thwaites Glacier West Antarctica |
geographic_facet |
Amundsen Sea Anet Antarctic Ellsworth Mountains Mount Takahe Pine Island Glacier Takahe Thwaites Glacier West Antarctica |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Pine Island Pine Island Glacier Thwaites Glacier West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Pine Island Pine Island Glacier Thwaites Glacier West Antarctica |
op_source |
Geochemistry, Geophysics, Geosystems, Vol 22, Iss 2, Pp n/a-n/a (2021) |
op_relation |
https://doi.org/10.1029/2020GC009471 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2020GC009471 https://doaj.org/article/dc78b009d54e44f5a3790c0211496072 |
op_doi |
https://doi.org/10.1029/2020GC009471 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
22 |
container_issue |
2 |
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1784263475581681664 |