LGM ice sheet extent in the Weddell Sea: evidence for diachronous behavior of Antarctic Ice Sheets

摘要: Abstract Inaccessibility due to harsh weather conditions and perennial sea ice has resulted in the Weddell Sea being one of more under-studied regions Antarctica. Re-examination existing cores unpublished multibeam bathymetric data provide new insight into LGM configuration sheet region. Sediment from eastern continental shelf, where East Antarctic Ice Sheet (EAIS) drains, display a retreat stratigraphy with distal glacimarine sediments overlying proximal till. The distinction between is based on degrees marine influence grain-size distributions foraminiferal abundance diversity. Glacimarine yielded AMS radiocarbon ages that span past 30,476 cal yr BP, indicating EAIS shelf occurred prior LGM. Multibeam swath bathymetry show mega-scale glacial lineations two troughs southern which indicates existence streams draining West (WAIS). More subtle within Filchner Trough imply sluggish flow across bedrock older strata this trough. Although there are no absolutely constrain timing grounding event we interpret as age their pristine nature. This interpretation consistent results other sectors compelling evidence for significant WAIS advance during exists. In Sea, apparent diachronous behavior onshore studies.