The sheer force of great ice sheets being carried to the sea creates the seismic signals, which can be used to measure the rate at which the massive island’s ice cap is melting.
Seismologist Meredith Nettles and colleagues, of Columbia University’s Lamont-Doherty Earth Observatory, write in an article to be published in the journal Geophysical Research Letters that a disturbing trend in recent years is that the ice quakes are expanding northward.
This means that the ice sheet is not only deteriorating at an accelerating pace, but the melt is expanding from warmer areas of Greenland in the south to cooler, formerly stable areas in the north.
Nettles says that 2012 appears on track to surpass 2005 with a record number of glacial earthquakes in Greenland.
Last year produced the second-highest number ever detected.