Title Glacial/interglacial ice-stream stability in the Weddell Sea Embayment, Antarctica
Author Hein, A.S.; Fogwill, C.J.; Sugden, D.E.; Xu, S.
Author Affil Hein, A.S., University of Edinburgh, School of GeoSciences, Edinburgh, United Kingdom. Other: University of New South Wales, Australia; Scottish Universities Environmental Research Centre, United Kingdom
Source Earth and Planetary Science Letters, 307(1-2), p.211-221. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012- 821X
Publication Date July 1, 2011
Notes In English. 59 refs. GeoRef Acc. No: 309681. CRREL Acc. No: 65006417
Index Terms aluminum; glaciation; global change; global warming; isotopes; metals; radioactive isotopes; Antarctica--East Antarctic ice sheet; Antarctica--Filchner Ice Shelf; Antarctica--Shackleton Range; Antarctica-- West Antarctic ice sheet; Al-26; alkaline earth metals; Antarctic ice sheet; Antarctica; Be-10; beryllium; Cenozoic; cosmogenic elements; East Antarctic ice sheet; elevation; exposure age; Filchner Ice Shelf; glacial environment; glacial rebound; ice streams; interglacial environment; isostatic rebound; last glacial maximum; middle Miocene; Miocene; Mount Provender; Mount Sheffield; Mount Skidmore; Neogene; Recovery Glacier; sea-level changes; Shackleton Range; Slessor Glacier; Tertiary; Transantarctic Mountains; Weddell Sea Embayment; West Antarctic ice sheet
Abstract The resilience of the Antarctic Ice Sheet and its effect on global sea level depends on the dynamics of ice streams. Antarctic ice streams are known to be responsive to changes at the ocean interface and, as expected, most have thinned in response to ocean warming and sea-level rise since the Last Glacial Maximum (LGM). Here we provide direct and unexpected evidence that points toward the glacial/interglacial stability of the Slessor and Recovery glaciers, ice streams of the East Antarctic Ice Sheet (EAIS) which merge with the West Antarctic Ice Sheet (WAIS) to form the Filchner Ice Shelf in the Weddell Sea embayment. Cosmogenic-nuclide measurements in the Shackleton Range suggest that the Slessor and Recovery ice streams were not significantly thicker than today during the LGM. We hypothesise that the glaciers did not thicken because the grounding line was not able to migrate seaward beyond the deep Thiel/Crary Trough beneath the Filchner Ice Shelf immediately offshore. This discovery reveals how a topographic threshold can affect the dynamics of ice streams. It also reduces uncertainties on the thickness, extent and volume of the Antarctic Ice Sheet in a large but unknown sector of the Antarctic Ice Sheet; it constrains the potential sea-level rise from Antarctica; it helps explain observed anomalies in glacio- isostatic adjustment; above all it suggests that the behaviour of the Atlantic-facing Weddell Sea sector of the WAIS contrasts with that of the Pacific-facing Ross and Amundsen Sea sectors.
URL http://hdl.handle.net/10.1016/j.epsl.2011.04.037
Publication Type journal article
Record ID 91381