Seven square miles of a Greenland glacier broke off in two days last week, leaving the calving edge of the ice sheet a mile further inland.
The NASA-funded researchers had been receiving imagery from several satellites, including Landsat, Terra, and Aqua, to get a broad view of ice changes.
Then, in the days leading up to the breakup, the team received pictures from DigitalGlobe’s WorldView 2 satellite showing large cracks and crevasses forming in the Jakobshavn Isbrae glacier.
On July 6 and 7, the break happened.
“While there have been ice breakouts of this magnitude from Jakonbshavn and other glaciers in the past, this event is unusual because it occurs on the heels of a warm winter that saw no sea ice form in the surrounding bay,” said Thomas Wagner, cryospheric program scientist for NASA.
“While the exact relationship between these events is being determined, it lends credence to the theory that warming of the oceans is responsible for the ice loss observed throughout Greenland and Antarctica.”
Jakobshavn Isbrae is located on the west coast of Greenland at latitude 69°N and has retreated around 30 miles over the past 160 years – six in just the past decade.
As the glacier has retreated, it has broken into a northern and southern branch. The breakup this week occurred in the north branch.
Jakobshavn is believed to be the single largest contributor to sea level rise in the northern hemisphere, and accounts for as much as 10 percent of all ice lost from Greenland.
Scientists are most concerned about losses from the south branch of the Jakobshavn, as the topography is flatter and lower than in the northern branch.
The researchers now plan to plant GPS sensors, cameras, and other scientific equipment on top of the ice sheet to monitor changes.