Four times more coastal glaciers in Greenland are at risk of melting

Up to four times more coastal glaciers in Greenland are at risk of accelerated melting than previously thought, say scientists who have mapped the region's coastal seafloor and bedrock beneath its massive ice sheet.

Researchers from NASA and the University of California Irvine in the US created the most comprehensive, accurate and high-resolution relief maps ever made of Greenland's bedrock and coastal seafloor.

Among the many data sources incorporated into the new maps is data from NASA's Ocean Melting Greenland campaign.

The OMG campaign surveyed large sections of the Greenland coast for the first time ever.

The new maps reveal that two to four times more oceanfront glaciers extend deeper than 200 metres below sea level than earlier maps showed.

That is bad news, because the top 182 metres of water around Greenland comes from the Arctic and is relatively cold, according to the study published in the journal Geophysical Research Letters