A research on the phenomena of thunderous shaking during ice break has been comprehensively studied by scientists in Greenland. The report, published in journal Science, has attributed the jiggle, some of which measured up to a magnitude of 5.0, to the backward movement of the glacier and to the subsequent change in water pressure.

The researchers claim that falling of icebergs from the glacier temporarily reverses the course and causes glacial earthquakes.

Meredith Nettles, a professor of earth science at Columbia University’s Lamont-Doherty Earth Observatory in New York City and the study co-author, stated, “It’s like taking a really strong spring, pushing on the front of it and just making it compress”.

Nettles explained that the splitting of the big chunk of ice is called ‘calving’ and when a calved iceberg falls into the ocean, it causes water displacement creating a low-pressure zone behind the iceberg, which is strong enough to suck water up from the ocean floor. Therefore, upward force on the Earth and the force of the falling iceberg produce a measurable seismic wave.

The research was conducted on Helheim Glacier in Greenland for 55 days in 2013. The researchers employed cameras, GPS sensors and the global seismographic network for recording theses glacial upheavals. The researchers were able to record ten such large-scale glacier retreat events and saw the glacier retreat by about 1 mile following the shaking events.

Nettles informed that Calving is an important component of the mass loss in both Greenland and Antarctica and glacial earthquakes induced by calving occur seven times more frequently than they did in the early 1990s.