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Deglacial Thinning of the Laurentide Ice Sheet in the Adirondack Mountains, New York, USA, Revealed by 36 Cl Exposure Dating
Author(s) -
Barth Aaron M.,
Marcott Shaun A.,
Licciardi Joseph M.,
Shakun Jeremy D.
Publication year - 2019
Publication title -
paleoceanography and paleoclimatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.927
H-Index - 127
eISSN - 2572-4525
pISSN - 2572-4517
DOI - 10.1029/2018pa003477
Subject(s) - deglaciation , ice sheet , geology , transect , thinning , glacial period , last glacial maximum , physical geography , elevation (ballistics) , climate change , wisconsin glaciation , oceanography , ice stream , paleontology , sea ice , cryosphere , geography , geometry , mathematics , forestry
Future changes in sea level will largely be dictated by changes in the world's ice sheets. Yet the magnitude and rate at which these ice sheets will respond to climate change remain uncertain, necessitating a deeper investigation into past ice sheet‐climate interactions. Numerous studies have documented the timing and pattern of Laurentide Ice Sheet margin retreat since the Last Glacial Maximum, but few studies have provided vertical constraints necessary for accurate sea level contribution estimates. Here we present 21 36 Cl ages from boulder and bedrock samples along vertical transects spanning ~1,000 m of relief from multiple peaks in the Adirondack Mountains of northeastern New York, USA. Our exposure ages span the Last Glacial Maximum through the last deglaciation, with the highest‐elevation sites (~1,500 m) ranging between 25 and 19 ka, and the lower elevation sites (≤1,300 m) between 16 and 13 ka. These data suggest gradual ice sheet thinning of 200 m initiated at ~20 ka followed by more rapid surface lowering of 1,000 m approximately coincident with Bølling‐Allerød warming.