A seismic transect across West Antarctica: Evidence for mantle thermal anomalies beneath the Bentley Subglacial Trench and the Marie Byrd Land Dome
West Antarctica consists of several tectonically diverse terranes, including the West Antarctic Rift System, a topographic low region of extended continental crust. In contrast, the adjacent Marie Byrd Land and Ellsworth-Whitmore mountains crustal blocks are on average over 1km higher, with the form...
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ftcwashingtonuni:oai:digitalcommons.cwu.edu:cotsfac-1148 2023-05-15T13:47:32+02:00 A seismic transect across West Antarctica: Evidence for mantle thermal anomalies beneath the Bentley Subglacial Trench and the Marie Byrd Land Dome Lloyd, Andrew J. Wiens, Douglas A. Nyblade, Andrew A. Anandakrishnan, Sridhar Aster, Richard C. Huerta, Audrey D. Wilson, Terry J. Dalziel, Ian W. D. Shore, Patrick J. Zhao, Dapeng 2015-12-15T08:00:00Z application/pdf https://digitalcommons.cwu.edu/cotsfac/148 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1148&context=cotsfac unknown ScholarWorks@CWU https://digitalcommons.cwu.edu/cotsfac/148 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1148&context=cotsfac © 2015. American Geophysical Union. All Rights Reserved. All Faculty Scholarship for the College of the Sciences West Antarctica upper mantle tomography Bentley Subglacial Trench Marie Byrd Land Geology Geophysics and Seismology text 2015 ftcwashingtonuni 2022-10-20T20:28:52Z West Antarctica consists of several tectonically diverse terranes, including the West Antarctic Rift System, a topographic low region of extended continental crust. In contrast, the adjacent Marie Byrd Land and Ellsworth-Whitmore mountains crustal blocks are on average over 1km higher, with the former dominated by polygenetic shield and stratovolcanoes protruding through the West Antarctic ice sheet and the latter having a Precambrian basement. The upper mantle structure of these regions is important for inferring the geologic history and tectonic processes, as well as the influence of the solid earth on ice sheet dynamics. Yet this structure is poorly constrained due to a lack of seismological data. As part of the Polar Earth Observing Network, 13 temporary broadband seismic stations were deployed from January 2010 to January 2012 that extended from the Whitmore Mountains, across the West Antarctic Rift System, and into Marie Byrd Land with a mean station spacing of ~90 km. Relative P and S wave travel time residuals were obtained from these stations as well as five other nearby stations by cross correlation. The relative residuals, corrected for both ice and crustal structure using previously published receiver function models of crustal velocity, were inverted to image the relative P and S wave velocity structure of the West Antarctic upper mantle. Some of the fastest relative P and S wave velocities are observed beneath the Ellsworth-Whitmore mountains crustal block and extend to the southern flank of the Bentley Subglacial Trench. However, the velocities in this region are not fast enough to be compatible with a Precambrian lithospheric root, suggesting some combination of thermal, chemical, and structural modification of the lithosphere. The West Antarctic Rift System consists largely of relative fast uppermost mantle seismic velocities consistent with Late Cretaceous/early Cenozoic extension that at present likely has negligible rift related heat flow. In contrast, the Bentley Subglacial Trench, a narrow ... Text Antarc* Antarctic Antarctica Ice Sheet Marie Byrd Land West Antarctica Central Washington University: ScholarWorks Antarctic Bentley Subglacial Trench ENVELOPE(-105.000,-105.000,-80.000,-80.000) Byrd Marie Byrd Land ENVELOPE(-130.000,-130.000,-78.000,-78.000) West Antarctic Ice Sheet West Antarctica Whitmore Mountains ENVELOPE(-104.000,-104.000,-82.500,-82.500) |
institution |
Open Polar |
collection |
Central Washington University: ScholarWorks |
op_collection_id |
ftcwashingtonuni |
language |
unknown |
topic |
West Antarctica upper mantle tomography Bentley Subglacial Trench Marie Byrd Land Geology Geophysics and Seismology |
spellingShingle |
West Antarctica upper mantle tomography Bentley Subglacial Trench Marie Byrd Land Geology Geophysics and Seismology Lloyd, Andrew J. Wiens, Douglas A. Nyblade, Andrew A. Anandakrishnan, Sridhar Aster, Richard C. Huerta, Audrey D. Wilson, Terry J. Dalziel, Ian W. D. Shore, Patrick J. Zhao, Dapeng A seismic transect across West Antarctica: Evidence for mantle thermal anomalies beneath the Bentley Subglacial Trench and the Marie Byrd Land Dome |
topic_facet |
West Antarctica upper mantle tomography Bentley Subglacial Trench Marie Byrd Land Geology Geophysics and Seismology |
description |
West Antarctica consists of several tectonically diverse terranes, including the West Antarctic Rift System, a topographic low region of extended continental crust. In contrast, the adjacent Marie Byrd Land and Ellsworth-Whitmore mountains crustal blocks are on average over 1km higher, with the former dominated by polygenetic shield and stratovolcanoes protruding through the West Antarctic ice sheet and the latter having a Precambrian basement. The upper mantle structure of these regions is important for inferring the geologic history and tectonic processes, as well as the influence of the solid earth on ice sheet dynamics. Yet this structure is poorly constrained due to a lack of seismological data. As part of the Polar Earth Observing Network, 13 temporary broadband seismic stations were deployed from January 2010 to January 2012 that extended from the Whitmore Mountains, across the West Antarctic Rift System, and into Marie Byrd Land with a mean station spacing of ~90 km. Relative P and S wave travel time residuals were obtained from these stations as well as five other nearby stations by cross correlation. The relative residuals, corrected for both ice and crustal structure using previously published receiver function models of crustal velocity, were inverted to image the relative P and S wave velocity structure of the West Antarctic upper mantle. Some of the fastest relative P and S wave velocities are observed beneath the Ellsworth-Whitmore mountains crustal block and extend to the southern flank of the Bentley Subglacial Trench. However, the velocities in this region are not fast enough to be compatible with a Precambrian lithospheric root, suggesting some combination of thermal, chemical, and structural modification of the lithosphere. The West Antarctic Rift System consists largely of relative fast uppermost mantle seismic velocities consistent with Late Cretaceous/early Cenozoic extension that at present likely has negligible rift related heat flow. In contrast, the Bentley Subglacial Trench, a narrow ... |
format |
Text |
author |
Lloyd, Andrew J. Wiens, Douglas A. Nyblade, Andrew A. Anandakrishnan, Sridhar Aster, Richard C. Huerta, Audrey D. Wilson, Terry J. Dalziel, Ian W. D. Shore, Patrick J. Zhao, Dapeng |
author_facet |
Lloyd, Andrew J. Wiens, Douglas A. Nyblade, Andrew A. Anandakrishnan, Sridhar Aster, Richard C. Huerta, Audrey D. Wilson, Terry J. Dalziel, Ian W. D. Shore, Patrick J. Zhao, Dapeng |
author_sort |
Lloyd, Andrew J. |
title |
A seismic transect across West Antarctica: Evidence for mantle thermal anomalies beneath the Bentley Subglacial Trench and the Marie Byrd Land Dome |
title_short |
A seismic transect across West Antarctica: Evidence for mantle thermal anomalies beneath the Bentley Subglacial Trench and the Marie Byrd Land Dome |
title_full |
A seismic transect across West Antarctica: Evidence for mantle thermal anomalies beneath the Bentley Subglacial Trench and the Marie Byrd Land Dome |
title_fullStr |
A seismic transect across West Antarctica: Evidence for mantle thermal anomalies beneath the Bentley Subglacial Trench and the Marie Byrd Land Dome |
title_full_unstemmed |
A seismic transect across West Antarctica: Evidence for mantle thermal anomalies beneath the Bentley Subglacial Trench and the Marie Byrd Land Dome |
title_sort |
seismic transect across west antarctica: evidence for mantle thermal anomalies beneath the bentley subglacial trench and the marie byrd land dome |
publisher |
ScholarWorks@CWU |
publishDate |
2015 |
url |
https://digitalcommons.cwu.edu/cotsfac/148 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1148&context=cotsfac |
long_lat |
ENVELOPE(-105.000,-105.000,-80.000,-80.000) ENVELOPE(-130.000,-130.000,-78.000,-78.000) ENVELOPE(-104.000,-104.000,-82.500,-82.500) |
geographic |
Antarctic Bentley Subglacial Trench Byrd Marie Byrd Land West Antarctic Ice Sheet West Antarctica Whitmore Mountains |
geographic_facet |
Antarctic Bentley Subglacial Trench Byrd Marie Byrd Land West Antarctic Ice Sheet West Antarctica Whitmore Mountains |
genre |
Antarc* Antarctic Antarctica Ice Sheet Marie Byrd Land West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Marie Byrd Land West Antarctica |
op_source |
All Faculty Scholarship for the College of the Sciences |
op_relation |
https://digitalcommons.cwu.edu/cotsfac/148 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1148&context=cotsfac |
op_rights |
© 2015. American Geophysical Union. All Rights Reserved. |
_version_ |
1766247270150307840 |