Scientists studying mysterious glacial earthquakes in Greenland have now finally understood why these earthquakes have become seven times more common in the past 20 years. Researchers during the study focused on Greenland’s Helheim Glacier.

After-in-depth monitoring of Greenland’s Helheim Glacier, researchers have discovered that large ice chunks that fall into ocean could create large force and push the glacier backwards.

This also causes a rapid change in water pressure which causes serious seismic events, like tsunami waves and moderate earthquakes.

Findings of the study published Thursday in Science magazine showed that glacial earthquakes are usually associated with ‘calving’, or the splitting of ice from large glaciers.

Explaining the process, researchers said as the ice fragments tumble into the ocean, they are sometimes accompanied by violent rumbling. But until now, researchers didn’t know why calving caused such a thunderous reaction on solid ground.

Meredith Nettles and colleagues for 55 days used GPS sensors and cameras to monitor the Helheim Glacier. They found that the force of calving ice was enough to push back against the glacier.

Ms. Nettles, a professor of earth science at Columbia University's Lamont-Doherty Earth Observatory, in an interview with LiveScience, said, “It’s like taking a really strong spring, pushing on the front of it and just making it compress. The glacier moves backward for a few minutes before springing forward again and moving as normal”.

The falling ice plummets into the ocean below. As a result, a large amount of water is displaced.
The gap between the iceberg and the glacier floods rapidly, leaving a powerful low-pressure zone in its wake. This movement pulls water up from the ocean floor, exerting significant upward force.

Co-author and Swansea University professor Timothy James told LiveScience that through calving, Greenland glaciers can lose up to 400 gigatons of ice every year.