02638nas a2200265   4500000000100000008004100001260001600042653002400058653001300082653001600095653002900111653002800140100001400168700002100182700001700203700002200220700001400242700001700256245011700273856007100390300001000461490000800471520187900479020001402358       2017                            d  c2017/04/01/10aIceberg ploughmarks10aIcebergs10aPleistocene10aWest Spitsbergen Current10aWestern Svalbard margin1 aFang Zhao1 aTimothy Minshull1 aAnya Crocker1 aJulian Dowdeswell1 aShiguo Wu1 aSimon Soryal00aPleistocene iceberg dynamics on the west Svalbard margin: Evidence from bathymetric and sub-bottom profiler data  uhttp://www.sciencedirect.com/science/article/pii/S0277379117300860  a30-440 v1613 a<p> Large icebergs leave evidence of their drift via ploughing of the seabed, thereby providing a geological record of episodes of calving from thick ice sheets. We interpret large-scale curvilinear depressions on the western Svalbard margin as ploughmarks produced by the keels of icebergs that grounded on the seafloor as they drifted through this area. Iceberg ploughmarks were identified at modern water depths between 300\&nbsp;m and 1000\&nbsp;m and in two distinct stratigraphic units. Combining data from sediment cores with seismic stratigraphy from sub-bottom profiler data suggests that the ploughmarks developed in two phases: (1) during Marine Isotope Stage (MIS) 6; and (2) during MIS 2, indicating the presence of large drifting icebergs on the western Svalbard margin during both the Late Saalian and Late Weichselian glaciations. Sediment-core data along the western Svalbard margin indicate a sharp increase in mass-transported sediments dated at 23.7\&nbsp;\textpm\&nbsp;0.2 ka, consistent with the MIS 2 age of the younger iceberg-ploughed surface. The ploughmarks are oriented in two main directions: SW-NE and S-N. S-N oriented ploughmarks, which shallow to the north, indicate iceberg drift from the south with a SW\textendashNE component marking the zone of splitting of the West Spitsbergen Current (WSC) into the Yermak Slope Current (YSC) and North Spitsbergen Current (NSC). Large MIS 6 and MIS 2 icebergs most likely had an Arctic Ocean source. We suggest that these icebergs probably left the Arctic Ocean southward through Fram Strait and circulated within the Norwegian-Greenland Sea before being transported northwards along the Svalbard margin by the WSC. An additional likely source of icebergs to the western Svalbard margin during MIS 2 was the ice-sheet terminating in the western Barents Sea, from which icebergs drifted northward.</p>  a0277-3791