Ice sheet sources of sea level rise and freshwater discharge during the last deglaciation
Article first published online: 22 DEC 2012
©2012. American Geophysical Union. All Rights Reserved.
Reviews of Geophysics
Volume 50, Issue 4, December 2012
How to Cite
2012), Ice sheet sources of sea level rise and freshwater discharge during the last deglaciation, Rev. Geophys., 50, RG4007, doi:10.1029/2011RG000371., and (
- Issue published online: 22 DEC 2012
- Article first published online: 22 DEC 2012
- Manuscript Accepted: 25 SEP 2012
- Manuscript Revised: 22 SEP 2012
- Manuscript Received: 22 AUG 2011
- ice sheets;
- sea level
 We review and synthesize the geologic record that constrains the sources of sea level rise and freshwater discharge to the global oceans associated with retreat of ice sheets during the last deglaciation. The Last Glacial Maximum (∼26–19 ka) was terminated by a rapid 5–10 m sea level rise at 19.0–19.5 ka, sourced largely from Northern Hemisphere ice sheet retreat in response to high northern latitude insolation forcing. Sea level rise of 8–20 m from ∼19 to 14.5 ka can be attributed to continued retreat of the Laurentide and Eurasian Ice Sheets, with an additional freshwater forcing of uncertain amount delivered by Heinrich event 1. The source of the abrupt acceleration in sea level rise at ∼14.6 ka (meltwater pulse 1A, ∼14–15 m) includes contributions of 6.5–10 m from Northern Hemisphere ice sheets, of which 2–7 m represents an excess contribution above that derived from ongoing ice sheet retreat. Widespread retreat of Antarctic ice sheets began at 14.0–15.0 ka, which, together with geophysical modeling of far-field sea level records, suggests an Antarctic contribution to this meltwater pulse as well. The cause of the subsequent Younger Dryas cold event can be attributed to eastward freshwater runoff from the Lake Agassiz basin to the St. Lawrence estuary that agrees with existing Lake Agassiz outlet radiocarbon dates. Much of the early Holocene sea level rise can be explained by Laurentide and Scandinavian Ice Sheet retreat, with collapse of Laurentide ice over Hudson Bay and drainage of Lake Agassiz basin runoff at ∼8.4–8.2 ka to the Labrador Sea causing the 8.2 ka event.