Englacial Architecture and Age-Depth Constraints Across the West Antarctic Ice Sheet

• Published in: Geophysical Research Letters
• Main Authors: Ashmore, David W, Bingham, Robert G, Ross, Neil, Siegert, Martin, Jordan, Tom A, Mair, Douglas WF
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union (AGU) 2020
• Subjects: Antarctic; Byrd; Weddell; Weddell Sea; West Antarctic Ice Sheet; Antarc*; ice core; Ice Sheet
• Online Access: http://livrepository.liverpool.ac.uk/3077420/; https://doi.org/10.1029/2019gl086663; http://livrepository.liverpool.ac.uk/3077420/1/2020_ashmore_GRL.pdf

The englacial stratigraphic architecture of internal reflection horizons (IRHs) as imaged by ice-penetrating radar (IPR) across ice sheets reflects the cumulative effects of surface mass balance, basal melt, and ice flow. IRHs, considered isochrones, have typically been traced in interior, slow-flowing regions. Here, we identify three distinctive IRHs spanning the Institute and Möller catchments that cover 50% of West Antarctica's Weddell Sea Sector and are characterized by a complex system of ice stream tributaries. We place age constraints on IRHs through their intersections with previous geophysical surveys tied to Byrd Ice Core and by age-depth modeling. We further show where the oldest ice likely exists within the region and that Holocene ice-dynamic changes were limited to the catchment's lower reaches. The traced IRHs from this study have clear potential to nucleate a wider continental-scale IRH database for validating ice sheet models.