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{"Abstract":["This dataset consists of detrital zircon U-Pb data from samples from the Amundsen Sea Embayment. The data are a product of the publication: "Reconstructing Eocene Antarctic river drainage from provenance analysis of Amundsen Sea Embayment sediments".\n\nIncluded are data from three Holocene sediment samples strategically located around the embayment to help characterise the detritus currently being eroded and deposited in the Amundsen Sea. Samples comprise of locations proximal to Pine Island Glacier and Thwaites Glacier, with a further sample to the north of Thwaites Glacier. A fourth sample consists of Cretaceous mudstone from a drill core from site PS104_20-2 in the Amundsen Sea Embayment.\n\nA second file contains a compilation of selected detrital zircon U-Pb dates from potential source areas around West Antarctica. These include the sedimentary rocks of the Swanson Formation and Ellsworth-Whitmore Mountains, as well as all published West Antarctic subglacial till data. Data from moraines in the Transantarctic Mountains are also included."]}
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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) 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;ML3.5) 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.
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- PAR ID:
- 10362113
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Geochemistry, Geophysics, Geosystems
- Volume:
- 22
- Issue:
- 2
- ISSN:
- 1525-2027
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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