Quantitative Analysis of the Maximum Rate and Minimum Duration for a 200 km Stepwise Retreat of the Bindschadler Ice Stream at ~11.5 cal kyr BP

• Main Author: E Kratochvil, Matthew
• Format: Text
• Language: unknown
• Published: LSU Digital Commons 2022
• Subjects: Ice Shelf Collapse; Geology; Geomorphology; Geophysics and Seismology; Glaciology; Amundsen Sea; Bindschadler Ice Stream; Ice Shelf
• Online Access: https://digitalcommons.lsu.edu/gradschool_theses/5573; https://doi.org/10.31390/gradschool_theses.5573; https://digitalcommons.lsu.edu/context/gradschool_theses/article/6640/viewcontent/Thesis_MattK_April26th_2022.pdf

Small-scale morainal ridges on the middle continental shelf of the Whales Deep Basin partly record the rapid opening of a 200-km grounding line embayment slightly after ~11.5 cal kyr BP. The overlapping pattern of backstepped moraines indicates that the grounding line oscillated back and forth during the retreat. Published sediment fluxes were combined with new sediment volume mapping of the moraines to infer the rates at which the grounding line retreated. The analyses indicate that the rates of grounding line retreat on the eastern flank of the embayment ranged from ~490 m a-1 to 1,300 m a-1. At the maximum rate of retreat, the embayment would have taken less than two centuries to open. The quantitative analysis provides a paleo-perspective on modern retreat. A paleo-modern comparison validates concern that glaciers in the Amundsen Sea sector are already experiencing an unstable retreat.