We’ve known for some time that the Greenland ice sheet is melting. worryingly fast. But a new study from Northwestern University and the University of Copenhagen has found that Greenland’s thousands of peripheral glaciers have entered a new and widespread state of rapid withdrawal.
In their research, the team used satellite images and rarely seen historic aerial photographs of the Greenland coast, to map the thousands of glaciers that are not part of the island’s vast central ice sheet. To complete the study, the researchers removed terrain distortion and used georeferencing techniques to identify the exact locations where the photographs were taken. This unique data allowed researchers to document and compare more than a thousand glaciers and the way they have changed over the past 130 years.
According Yarrow Axford, lead author of the Northwestern study, some of the historic photographs were taken from open-cockpit aircraft during early Greenland mapping missions. “Those old photographs expand the data set before the satellite era, when widespread observations of the cryosphere They are rare. “It is quite extraordinary that we can now provide long-term records for hundreds of glaciers, finally giving us the opportunity to document the response of Greenland glaciers to climate change for more than a century.”
The multi-year study has concluded that the rate of glacier retreat has doubled since 2000, and that rising air and ocean temperatures due to human induced climate change is the reason for this negative record. “Our activities over the next two decades will greatly affect these glaciers. “Every little increase in temperature really matters,” he said. Laura Larocathe first author of the study.