Past Ice-Ocean Interactions on the Sabrina Coast shelf, East Antarctica: Deglacial to Recent Paleoenvironmental Insights from Marine Sediments

• Main Author: Vadman, Kara J.
• Format: Doctoral or Postdoctoral Thesis
• Language: unknown
• Published: Digital Commons @ University of South Florida 2021
• Subjects: geochemistry; Holocene; paleoceanography; sediments; Climate; Geology; Antarctic; East Antarctic Ice Sheet; East Antarctica; Moscow University Ice Shelf; Sabrina Coast; Totten Glacier; Antarc*; Antarctica; ice core; Ice Sheet; Ice Shelf; Ice Shelves
• Online Access: https://digitalcommons.usf.edu/etd/9621; https://digitalcommons.usf.edu/context/etd/article/10818/viewcontent/Vadman_usf_0206D_16767.pdf

The East Antarctic Ice Sheet (EAIS) contains ~53 meters of sea level equivalent (SLE) ice, and observations suggest it is sensitive to ongoing and past climate change. The EAIS has traditionally been considered insensitive to climate perturbations because it is largely grounded above sea level. However, aerogeophysical surveys, oceanographic observations, and models indicate that large areas of the EAIS are grounded below sea level and contain 19.2 m SLE. Marine-based parts of the EAIS are thought to be located on inland-sloping beds that drain through marine terminating outlet glaciers, indicating large areas of the EAIS may be more sensitive to ongoing climate change than previously thought. Many of Antarctica’s marine outlet glaciers and fringing ice shelves are losing mass as warm ocean waters move across continental shelves toward deep glacial grounding lines. Predictions of future ice sheet response to climate change are limited by the short time-series of observations and the complexity of associated forcings and feedbacks. To accurately predict future Antarctic cryosphere response to ongoing ocean warming, it is critical to understand how Antarctica’s ice sheets responded to past climate variations. Antarctic margin marine geological records provide a longer-term perspective (up to millions of years) on current Antarctic ice retreat than instrumental and ice core records. Ice-proximal geologic records are crucial for understanding past regional ice dynamics near sensitive Antarctic outlet glacier systems. The Totten Glacier and Moscow University Ice Shelf systems on the Sabrina Coast, East Antarctica, drains a large, marine-based catchment system called the Aurora Subglacial Basin (ASB), which contains one eighth of the ice in East Antarctica. Oceanographic observations indicate that warm modified Circumpolar Deep Water (mCDW) flows across the continental shelf to access regional grounding lines, thus the ASB catchment might be susceptible to ice mass loss via ocean thermal forcing. Present estimates ...