In the summer of 2012, the Jakobshavn Glacier reached a record speed of more than 10 miles per year, or more than 150 feet per day, the European Geophysical Union in Munich, Germany, reported Monday.
The annually averaged speedup over the past couple of years is nearly three times what it was in the 1990s, researchers said.
"We are now seeing summer speeds more than four times what they were in the 1990s on a glacier, which at that time was believed to be one of the fastest, if not the fastest, glacier in Greenland," study lead author Ian Joughin of the University of Washington said.
The acceleration means the glacier is adding more and more ice to the ocean, contributing to sea-level rise, he said.
"We know that from 2000 to 2010 this glacier alone increased sea level by about 1 millimeter. With the additional speed it likely will contribute a bit more than this over the next decade," he said.
Widely believed to be the glacier that produced the large iceberg that sank the Titanic in 1912, the Jakobshavn Glacier drains the Greenland ice sheet into a deep ocean fjord on the coast of the island.
As the arctic region warms, Greenland glaciers such as the Jakobshavn have been thinning and calving more and more icebergs, the researchers said.