Glaciers on Svalbard survived the Holocene thermal optimum.

Abstract About 60% of Svalbard is covered by glaciers today, but many of these glaciers were much reduced in size or gone in the Early Holocene. High resolution modeling of the glacial isostatic rebound reveals that the largest glaciers in Nordaustlandet and eastern Spitsbergen survived the Early Holocene warming, while the smaller, more peripheral glaciers, especially in the northwest, started to form about 5,500 years ago, and reached 3/4 of their current size about 600 years ago. Relative sea level has been rising during the last few millennia in the north and western parts of Spitsbergen, while land still emerges in the remaining part of Svalbard. Here we show that this sea level rise in the northwest is caused by the regrowth of glaciers in the Mid- to Late Holocene that slowed down, and even reversed, the post-glacial isostatic uplift and caused the crust to subside over large areas of Spitsbergen. Highlights • Largest ice caps on Svalbard survived the Early Holocene warming. • Many cirque and valley glaciers re-formed 5500 years ago. • Regrowth of glaciers caused transgression in NW Svalbard last 2000 years. • Best Earth model has a thin lithosphere and low-viscosity asthenosphere. [ABSTRACT FROM AUTHOR]