The retreat of North America’s ice sheets in the latter years of the last ice age may have begun with “catastrophic” losses of ice into the North Pacific Ocean along the coast of modern-day British Columbia and Alaska, scientists say.
In a new study published October 1 in Science, researchers find that these pulses of rapid ice loss from what’s known as the western Cordilleran ice sheet contributed to, and perhaps triggered, the massive calving of the Laurentide ice sheet into the North Atlantic Ocean thousands of years ago. That collapse of the Laurentide ice sheet, which at one point covered large swaths of Canada and parts of the United States, ultimately led to major disturbances in the global climate (SN: 11/5/12).
The new findings cast doubt on the long-held assumption that hemispheric-scale changes in Earth’s climate originate in the North Atlantic (SN: 1/31/19). The study