Enigmatic Eastern Laurentide Ice Sheet deglaciation

Abstract

The retreat of the Laurentide Ice Sheet at the end of the last ice age represents a dramatic sequence of environmental change that is evident in geological records across North America. The details of when, where, how, and why the Laurentide Ice Sheet collapsed are critical to understanding ocean‐atmosphere‐ice dynamics during this period of significant global climate change. The retreat sequence along the eastern margin of the Laurentide Ice Sheet is especially relevant for understanding climate variability. Enormous amounts of freshwater were released into the North Atlantic following deglaciation, and an influx of freshwater into the North Atlantic Deep Water formation zone can potentially trigger abrupt climate changes. Determining the mechanisms and feedbacks involved in climate change at the end of the last ice age therefore requires an understanding of the relationship between the southern margin ice retreat and connected meltwater events to atmospheric and sea surface temperatures, ice‐rafting Heinrich events, sea level rise, and atmospheric greenhouse gas concentrations.