georefid:2012-087085SEDIS Publication Catalogue

ana.macario@awi.de

http://sedis.iodp.org/pub-catalogue/informationpointOfContact2013-07-08T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=10.1016/j.quascirev.2011.03.0132011-01-01publicationgeorefid:2012-087085doi:10.1016/j.quascirev.2011.03.013Sarkar, SudiptaNational Oceanography Centre, Southampton, United KingdomauthorBerndt, ChristianauthorChabert, AnneauthorMasson, Douglas G.authorMinshull, Timothy A.authorWestbrook, Graham K.authorElsevier, InternationalpublisherdocumentHardcopyQuaternary Science Reviews30 (13-14)1710-1725Ice streams are the fast-flowing zones of ice sheets that can discharge a large flux of ice. The glaciated western Svalbard margin consists of several cross-shelf troughs which are the former ice stream drainage pathways during the Pliocene-Pleistocene glaciations. From an integrated analysis of high-resolution multibeam swath-bathymetric data and several high-resolution two-dimensional reflection seismic profiles across the western and northwestern Svalbard margin we infer the ice stream flow directions and the deposition centres of glacial debris that the ice streams deposited on the outer margin. Our results show that the northwestern margin of Svalbard experienced a switching of a major ice stream. Based on correlation with the regional seismic stratigraphy as well as the results from ODP 911 on Yermak Plateau and ODP 986 farther south on the western margin of Spitsbergen, off Van Mijenfjord, we find that first a northwestward flowing ice stream developed during initial northern hemispheric cooling (starting approximately 2.8-2.6 Ma). A switch in ice stream flow direction to the present-day Kongsfjorden cross-shelf trough took place during a glaciation at approximately 1.5 Ma or probably later during an intensive major glaciation phase known as the 'Mid-Pleistocene Revolution' starting at approximately 1.0 Ma. The seismic and bathymetric data suggest that the switch was abrupt rather than gradual and we attribute it to the reaching of a tipping point when growth of the Svalbard ice sheet had reached a critical thickness and the ice sheet could overcome a topographic barrier. Abstract Copyright (2011) Elsevier, B.V.completedStratigraphyApplied geophysicsArctic OceanArctic regionbathymetryCenozoicgeophysical methodsgeophysical profilesgeophysical surveysglacial environmentglacial geologyglaciomarine environmentice sheetsice streamsKings BayLeg 151Leg 162lithofacieslower Pleistocenemarine environmentNeogeneNorwegian SeaOcean Drilling ProgramODP Site 911ODP Site 986paleoenvironmentPleistocenePlioceneQuaternaryreflection methodsseismic methodsseismic profilesseismic stratigraphySpitsbergensurveysSvalbardTertiaryupper PlioceneVan MijenfordYermak Plateauurn:org.iodp:exp:151urnlargerWorkCitationcampaignurn:org.iodp:exp:162urnlargerWorkCitationcampaignurn:org.iodp:exp:151:site:911urnlargerWorkCitationstudyurn:org.iodp:exp:151urnlargerWorkCitationcampaignurn:org.iodp:exp:162:site:986urnlargerWorkCitationstudyurn:org.iodp:exp:162urnlargerWorkCitationcampaignEnglishgeoscientificInformation-9.044010.000077.202580.2829