[M-IS14] 古気候・古海洋変動

[MIS14-14] Evaluating Eurasian ice sheet reconstructions based on the DATED-2 margin chronology using paleo sea level constraints

★Invited Papers

*Evan James Gowan¹、Anna Hughes²、Richard Gyllencreutz³、Jan Mangerud⁴、John Inge Svendsen⁴、Jo Brendryen⁴、Riccardo Riva⁵ (1.Kumamoto University, Kumamoto, Japan、2.University of Manchester, Manchester, United Kingdom、3.Stockholm University, Stockholm, Sweden、4.University of Bergen, Bergen, Norway、5.Delft University of Technology, Delft, Netherlands)

キーワード：sea level, ice sheets, glacial isostatic adjustment, paleotopography

Vertical land motion due to glacial isostatic adjustment is the primary driver of past sea level changes in glaciated areas. The rate of past sea level change can be determined through dated geological and geomorphic sea level proxies. Modelling the trajectory of past sea level changes is a classical way to invert for the ice volume history of ice sheets. The Global Archive of Paleo Sea Level Indicators and Proxies (GAPSLIP) is a freely available archive of paleo sea level proxies designed to be used for comparing these data to calculated sea level from glacial isostatic models. Version 3.0 of GAPSLIP has complete coverage of Europe, including a new compilation from Iceland. We use these data to evaluate ice sheet reconstructions of the Eurasian Ice Sheet Complex with the new DATED-2 ice-margin chronology, during the last glaciation (40,000 to 10,000 years before present). DATED-2 contains minimum, most-credible and maximum ice extent scenarios. From our results, it is not possible to rule out any of the scenarios in most areas. It is possible to account for differences in duration of ice cover by an overall thinning or thickening of the ice sheet, and still match the observed paleo sea level changes. The consequence is that the maximum possible ice volume at the Last Glacial Maximum depends on the reconstructed ice margin history, which is, in turn, based on multiple lines of chronological and geological evidence constraining former ice cover.