Publication Date:
2022-02-15
Description:
Reconstructions of sea-surface conditions during the Holocene were achieved using three sediment cores from
northeastern Baffin Bay (GeoB19948-3 and GeoB19927-3) and the Labrador Sea (GeoB19905-1) along a north–
south transect based on sea-ice IP25 and open-water phytoplankton biomarkers (brassicasterol, dinosterol and HBI
III). In Baffin Bay, sea-surface conditions in the Early Holocene were characterized by extended (early) spring sea ice
cover (SIC) prior to 7.6 ka BP. The conditions in the NE Labrador Sea, however, remained predominantly ice-free in
spring/autumn due to the enhanced influx of Atlantic Water (West Greenland Current,WGC) from11.5 until ~9.1 ka
BP, succeeded by a period of continued (spring–autumn) ice-free conditions between 9.1 and 7.6 ka BP corresponding
to the onset of Holocene Thermal Maximum (HTM)-like conditions. A transition towards reoccurring ice-edge and
significantly reduced SIC conditions in Baffin Bay is evident in the Middle Holocene (~7.6–3 ka BP) probably caused
by the variations in the WGC influence associated with the ice melting and can be characterized as HTM-like
conditions. These HTM-like conditions are predominantly recorded in the NE Labrador Sea area shown by (spring–
autumn) ice-free conditions from 5.9–3 ka BP. In the Late Holocene (last ~3 ka), our combined proxy records from
eastern Baffin Bay indicate low in-situ ice algae production; however, enhanced multi-year (drifted) sea ice in this area
was possibly attributed to the increased influx of Polar Water mass influx and may correlate with the Neoglacial
cooling. The conditions in the NE Labrador Sea during the last 3 ka, however, continued to remain (spring–autumn)
ice-free. Our data from the Baffin Bay–Labrador Sea transect suggest a dominant influence of meltwater influx on sea ice
formation throughout the Holocene, in contrast to sea-ice records from the Fram Strait area,which seem to follow
predominantly the summer insolation trend.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
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isiRev
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