Antarctic Peninsula Ice Sheet evolution during the Cenozoic Era

摘要: The Antarctic Peninsula region is currently undergoing rapid environmental change, resulting in the thinning, acceleration and recession of glaciers sequential collapse ice shelves. It important to view these changes context long-term palaeoenvironmental complexity understand key processes controlling sheet growth recession. In addition, numerical models require detailed geological data for tuning testing. Therefore, this paper systematically holistically reviews published evidence Ice Sheet variability each locality throughout Cenozoic, brings together prevailing consensus extent, character behaviour glaciations region. Major contributions include a downloadable database 186 terrestrial marine calibrated dates; an original reconstruction LGM sheet; new series isochrones detailing retreat following LGM. Glaciation Antarctica was initiated around Eocene/Oligocene transition East Antarctica. Palaeogene records glaciation are primarily restricted King George Island, where glacigenic sediments provide record early glaciations, but with modification far-travelled erratics by local South Shetland Island caps. Evidence Neogene derived from James Ross glaciovolcanic strata indicate that thicknesses reached 500–850 m during glacials. This suggests draped, rather than drowned, topography. Marine geophysical investigations multiple advances time. Seismic profiling continental shelf-slope deposits indicates up ten large Early Pleistocene, when dominated 40 kyr cycles. Glacials became more pronounced, reaching shelf edge, longer duration Middle Pleistocene. During Late repeated glacials shelves inhibited iceberg rafting. Last Glacial Maximum (LGM) occurred at 18 ka BP, after which transitional glaciomarine on ice-sheet retreat. contains bathymetric troughs, were repeatedly occupied streams Pleistocene glaciations. Retreat episodic Weddell Sea, readvances ice-flow direction, Bellingshausen Sea. late Holocene Epoch characterised fluctuations conditions, associated glacial readvances. However, has been subsumed warming ice-shelf twentieth century.