Neoglacial Behavior of Spitsbergen Valley Glaciers and Relationship to Sea Level and Climate

Understanding the timescales at which glaciers and ice sheets respond to climate change is critical for predicting how they may respond to anthropogenic climate change and affect near-future sea-level rise. The Neoglacial period (ca., 4-0.5 ka) is of particular interest, as it includes several centennial-scale climate oscillations, which likely influenced glacier advance and retreat in the North Atlantic. In many regions, the Neoglacial period culminated in the Little Ice Age, when many regions, particularly in Europe and western Greenland, reached their coldest temperatures and largest ice extents since the earliest Holocene. However, several recent studies suggest an earlier, more extensive advance that ended 1.5 ka and may occurred in parts of the North Atlantic, including Baffin Island, southern Greenland, and Spitsbergen. The end of this event is concurrent with an 5 cm rise in global-mean sea level. Here, we test the hypothesis that there was a significant pre-Little Ice Age advance of Arctic glaciers using 10Be cosmogenic surface exposure ages from western Spitsbergen, one of the largest sources of sea-level rise predicted for the near future. These exposure ages come from large moraines just outboard of the Little Ice Age extents of three glaciers), indicating an earlier advance of ice. Combining other glacial records from several glaciological regimes, including two cirque glaciers and one marine-terminating surge-type glacier and comparison of our results to sea level will place our Arctic Spitsbergen study into a regional to global context.