Pleistocene dynamics of the interior East Antarctic ice sheet

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dc.contributor.authorLilly, Ken_AU
dc.contributor.authorFink, Den_AU
dc.contributor.authorFabel, Den_AU
dc.contributor.authorLambeck, Ken_AU
dc.date.accessioned2010-07-20T04:37:48Zen_AU
dc.date.available2010-07-20T04:37:48Zen_AU
dc.date.issued2010-08en_AU
dc.date.statistics2010-08en_AU
dc.description.abstractCurrent models describing past configurations of the East Antarctic ice sheet are poorly constrained by observations. Exposure dating of bedrock surfaces using in situ–produced cosmogenic nuclides provides an ideal tool for directly constraining former changes in ice sheet elevation. We present cosmogenic radionuclide 10Be and 26Al measurements in bedrock surfaces and glacially transported cobbles in the Grove Mountains, a group of nunataks within the slow-flowing interior ice sheet dome, hundreds of kilometers from the coastal ice margin and from ice streams. Samples were collected in vertical transects over 500 m of relief. Minimum bedrock and erratic exposure ages show a trend of increasing age with height above the ice sheet, spanning a period from 0.3 to 4.0 Ma and 50–900 ka, respectively. No evidence was found for thicker ice at the Last Glacial Maximum compared to modern ice thickness. The older bedrock exposure ages of 2.5–4.0 Ma require steady-state erosion rates of <0.1 mm k.y.−1. The measured two-isotope bedrock exposure ages are successfully modeled when changes in surface elevation of the ice sheet are described by a combination of linear long-term ice surface lowering and shorter term high-frequency glacial-interglacial oscillations. The best-fit model requires a long-term thinning rate of 50 m m.y.−1 and an elevation change of 100 m over a 100 k.y. glacial cycle. © 2010, Geological Society of Americaen_AU
dc.identifier.citationLilly, K., Fink, D., Fabel, D., & Lambeck, K. (2010). Pleistocene dynamics of the interior East Antarctic ice sheet. Geology, 38(8), 703-706. doi:10.1130/G31172x.1en_AU
dc.identifier.govdoc1925en_AU
dc.identifier.issn0091-7613en_AU
dc.identifier.issue8en_AU
dc.identifier.journaltitleGeologyen_AU
dc.identifier.pagination703-706en_AU
dc.identifier.urihttp://dx.doi.org/10.1130/G31172x.1en_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/1825en_AU
dc.identifier.volume38en_AU
dc.language.isoenen_AU
dc.publisherGeological Society of Americaen_AU
dc.subjectAntarctic regionsen_AU
dc.subjectIceen_AU
dc.subjectPleistocene epochen_AU
dc.subjectDynamicsen_AU
dc.subjectLevelsen_AU
dc.subjectEnvironmental exposureen_AU
dc.titlePleistocene dynamics of the interior East Antarctic ice sheeten_AU
dc.typeJournal Articleen_AU
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