Asynchronous instability of the North American-Arctic and Greenland ice sheets during the last deglaciation

QUATERNARY SCIENCE REVIEWS

卷:164

Article

Jackson, Rebecca¹  Carlson, Anders E.²  Hillaire-Marcel, Claude³  Wacker, Lukas⁴  Vogt, Christoph⁵  Kucera, Michal¹ 

[1] MARUM Ctr Marine Environm Sci, Leobener Str 8, D-28359 Bremen, Germany

[2] Oregon State Univ, Coll Earth Ocean & Atmospher Sci, Corvallis, OR 97331 USA

[3] Univ Quebec, Geotop, CP 8888,Succ Ctr Ville, Montreal, PQ H3C 3P8, Canada

[4] ETHZ, Lab Ion Beam Phys, Otto Stern Weg 5, CH-8093 Zurich, Switzerland

[5] Univ Bremen, Dept Geosci, Zentrallabor Kristallog & Angew Mat Wissensch ZEK, Klagenfurter Str, D-28359 Bremen, Germany

关键词: Quaternary;    Glaciology (inc. paleo-ice sheets);    Sedimentology - marine cores;    Baffin Bay;    Last deglaciation;    Ice-sheet retreat;    Radiocarbon dating;    Detrital carbonate events;   

DOI  :  10.1016/j.quascirev.2017.03.020

来源: Elsevier

【 摘 要 】

The chronology of deglacial meltwater pulses from the Laurentide Ice Sheet is well documented. However, the deglacial history of the North American-Arctic (north-eastern Laurentide and Innuitian) and western Greenland ice sheets draining into the Labrador Sea via Baffin Bay is less well constrained. Here we present new high-resolution, radiocarbon-dated records from the central Baffin Bay spanning similar to 17 to 10 kyr BP and documenting the full deglacial history of Baffin Bay. Sedimentological and geochemical data confirm the presence of two periods of enhanced detrital carbonate delivery, termed Baffin Bay Detrital Carbonate Events (BBDCs). These events are dated to similar to 14.2-13.7 kyr BP and similar to 12.7-11 kyr BP. They are synchronous across Baffin Bay and their mineralogical signature indicates a common source of detrital carbonate from northern Baffin Bay. The first event, BBDC 1, postdates Heinrich Event 1 and the second event, BBDC 0, predates the recently revised timing of Heinrich Event 0. The onset of the BBDC events appears not to be systematically linked to Greenland temperature change as they occur during both interstadial and stadial periods. This indicates that deglaciation of North American-Arctic and western Greenland ice sheets with the associated iceberg and meltwater discharge were decoupled from the dominant North Atlantic climate mode, where iceberg discharge events from the Laurentide Ice Sheet occurred during stadial periods. (C) 2017 Elsevier Ltd. All rights reserved.

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