THE LAST EURASIAN ICE SHEETS: A CHRONOLOGICAL DATABASE AND TIME-SLICE RECONSTRUCTION (DATED)

We present a new time-slice reconstruction documenting the changing limits of the Eurasian (British-Irish-Scandinavian-Svalbard-Barents-Kara-Sea) Ice Sheets during the last glaciation (40-10 ka) based on a database of over 5000 dates and ice-margin position evidence. The ice-sheet limits are delineated every 1000 years for the last 25 ka, and at uneven intervals back to ~40 ka. The timing of both maximum extent and retreat were spatially variable across the ice sheet area, reflecting regional contrasts in forcing mechanisms and geographical setting. Maximum limits were reached up to 3000 years earlier in the west than in the east.

We have evaluated and integrated all accountable uncertainties (e.g. in dating results, stratigraphy, moraine correlation) and present them collectively in terms of uncertainty in the ice-margin position. Thus we present maximum, minimum, and most-credible ice-limit positions for each time-slice. Each date in the database is attributed to the source publication, fully documented with information relevant to its interpretation and searchable by metadata including original author, location, dated material, dating technique, stratigraphic position or setting, derived age and associated errors, pertinent comments from the source publication and sample elevation or depth, core name, laboratory id and/or sample name as applicable. For internal consistency all radiocarbon ages have been recalibrated using the most recent calibration curves (INTCAL/MARINE13) and all terrestrial cosmogenic nuclide (TCN) exposure ages are recalculated using the same production rate and scaling model. The uncalibrated ¹⁴C and TCN ages as reported in the source publications are also given. The database and reconstructions will be made available to download and updated on an on-going basis as new information becomes published and future versions will also include landform evidence to constrain ice-sheet geometry (e.g. ice flow patterns, ice-stream locations and ice thickness). The first version will be submitted to Boreas during the fall 2014.