Ancient Collapse of Ice Sheet Led to Rapid, Catastrophic Rise of Sea Levels

The partial collapse of the Eurasian Ice Sheet nearly 15,000 years ago caused global sea levels to rise by as much as 45 feet in less than 400 years.

(CN) — As greenhouse gas emissions hasten the thinning of polar ice, scientists revealed details Monday of the collapse of Eurasian Ice Sheet about 14,650 years ago and its devastating effects, giving researchers an idea of what a rapid collapse of vulnerable ice sheets could do in modern times.

Contour lines represent ice margins at different stages of the deglaciation. (Photo courtesy of the General Bathymetric Chart of the Oceans)

The study, published in the journal Nature Geoscience by a team of researchers from the University of Bergen in Norway, analyzed the collapse and discovered that it led to a 39-to 45-foot global sea-level rise in less than 400 years.

Known as the Last Glacial Maximum, this period in Earth’s history from about 33,000 years ago featured low global temperatures and massive ice sheets covering much of the Northern Hemisphere.

The scientists theorize around 14,600 years ago, an event known as Meltwater Pulse 1A that featured a period of sudden climate warming coincided with the melting of the Eurasian Ice Sheet. The ice sheet’s maximum ice volume was about three times greater than the modern-day Greenland Ice Sheet, which covers approximately 660,000 square miles.

Scientists have long thought that the melting of the Eurasian Ice Sheet happened too early to occur within the timeframe of Meltwater Pulse 1A. Monday’s study concludes otherwise, as researchers examined age data of sediment cores from the Norwegian Sea.

Using a reconstruction model, the research team found the melting of the ice sheet occurred at the same time of the meltwater event.

“The detailed age reconstruction showed that the melting of part of the Eurasian Ice Sheet — which is comparable in size to the modern West Antarctic Ice Sheet — was coincident with the Meltwater Pulse 1A event, and that the ice-sheet collapse was fast, occurring over a period of less than 500 years,” the study’s authors wrote.

The researchers believe the melting of the ice sheet may have contributed 20% to 60% of the rapid sea-level rise. From 1993 to 2017, satellite data has found that the global sea-level is rising about 12 inches every century. While not as rapid as the meltwater event, recent evidence shows that modern glacial melt is increasing thanks to greenhouse gas emissions.

The scientists said their research “may provide a better understanding of the vulnerability of modern ice sheets to such rapid collapse today.”

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