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Sortable silt cycles in Svalbard slope sediments 74–0 ka
Author(s) -
Jessen Simon P.,
Rasmussen Tine L.
Publication year - 2015
Publication title -
journal of quaternary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.142
H-Index - 94
eISSN - 1099-1417
pISSN - 0267-8179
DOI - 10.1002/jqs.2807
Subject(s) - younger dryas , geology , oceanography , meltwater , thermohaline circulation , stadial , silt , fjord , ocean gyre , climate change , climatology , glacial period , holocene , geomorphology , subtropics , fishery , biology
The grain size of sortable silt (SS, 10–63 μm) was studied in sediment core JM04‐025PC from a sediment drift on the lower part of the western Svalbard slope. The study aims to reconstruct the bottom current activity and intermediate water circulation in the Greenland Sea. The SS record covers the last 74 ka and shows consistent millennial‐scale oscillations in grain size. The youngest part of the record (<25 ka) is well correlated with the few available previously published reconstructions of grain size from the North Atlantic Ocean and the Nordic seas. Fining of SS occurs during four well‐known regional cold climatic intervals, the 8.2‐ka cold spell, the Younger Dryas and North Atlantic Heinrich Events H1 and H2, as well as during a local meltwater event at 14.4–14.7 ka, possibly coinciding with the Older Dryas. Also before 25 ka, grain size oscillated in pace with the Northern Hemisphere climate with finer grain sizes during cold periods and coarser grain sizes during warm periods. The fining of SS indicates reduced bottom current strength and reduced water exchange between the Greenland Sea and the Arctic Ocean during regional climate cooling events, and probably also reduced deep ocean convection in the Greenland Sea gyre.