High-resolution organic geochemical bulk parameter and biomarker records off eastern North Greenland

A high-resolution biomarker record was carried out on Polarstern Cruise PS93.1 (2015) to reconstruct past sea-ice variability off the continental eastern North Greenland shelf. This area is strongly influenced by cold surface waters and drift ice transported via East Greenland Current, meltwater pulses from the outlet glaciers of the Northeast Greenland Ice Stream and the build-up of landfast ice. The AMS 14C-dated Holocene Kastenlot Core PS93/025 reflects high sedimentation rates ranging between 25-30 cm/kyr over the past 10.2 ka. Organic bulk parameters, highly branched isoprenoids (IP25, HBI II and HBI III) and specific sterols were measured to provide insights into variations of the sea-ice conditions (regional and local sea-ice signal), oceanic and atmospheric circulation and the biotic response to these changes.These biomarker records show a reduced to variable sea-ice cover during the early Holocene between 10.2 and 9.3 ka, followed by a steady increase in sea-ice conditions during the mid-Holocene. During the last 5–6 ka, sea-ice conditions remained more stable representing a seasonal to marginal sea-ice situation. Based on our biomarker records, stable sea-ice edge conditions, with a fully developed polynya situation occurred since the last 1 ka.