Final Laurentide ice-sheet deglaciation and Holocene climate-sea level change

Quaternary Science Reviews
By: , and 

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Abstract

Despite elevated summer insolation forcing during the early Holocene, global ice sheets retained nearly half of their volume from the Last Glacial Maximum, as indicated by deglacial records of global mean sea level (GMSL). Partitioning the GMSL rise among potential sources requires accurate dating of ice-sheet extent to estimate ice-sheet volume. Here, we date the final retreat of the Laurentide Ice Sheet with 10Be surface exposure ages for the Labrador Dome, the largest of the remnant Laurentide ice domes during the Holocene. We show that the Labrador Dome deposited moraines during North Atlantic cold events at ∼10.3 ka, 9.3 ka and 8.2 ka, suggesting that these regional climate events helped stabilize the retreating Labrador Dome in the early Holocene. After Hudson Bay became seasonally ice free at ∼8.2 ka, the majority of Laurentide ice-sheet melted abruptly within a few centuries. We demonstrate through high-resolution regional climate model simulations that the thermal properties of a seasonally ice-free Hudson Bay would have increased Laurentide ice-sheet ablation and thus contributed to the subsequent rapid Labrador Dome retreat. Finally, our new 10Be chronology indicates full Laurentide ice-sheet had completely deglaciated by 6.7 ± 0.4 ka, which re quires that Antarctic ice sheets contributed 3.6–6.5 m to GMSL rise since 6.3–7.1 ka.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Final Laurentide ice-sheet deglaciation and Holocene climate-sea level change
Series title Quaternary Science Reviews
DOI 10.1016/j.quascirev.2016.09.014
Volume 152
Year Published 2016
Language English
Publisher Elsevier
Contributing office(s) National Research Program - Western Branch
Description 11 p.
First page 49
Last page 59
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