Researchers have filmed huge melt water lakes vanishing in hours from the vast unending Greenland ice sheet and opening giant crevices underneath. However scientists have explained a further outcome of this cataclysmic melting of huge mass of ice- earthquakes.
Details of how the melting of gigantic chunks of Greenland’s ice mass can cause glacial earthquakes has been explained in the journal Science by a team of researchers from Swansea University in the UK, the Lamont-Doherty Earth Observatory at Columbia University, and several other institutions.
In a nutshell, the paper explains how loss of Greenland’s ice Glacial can trigger quakes which are detectable across the globe. When large icebergs break off from the outer rims of tidal glaciers, they fall in the water and jam the glaciers backwards and results in a seismic incidence which can be detected across the seismic centers strung across the globe.
According to Meredith Nettles of thex University, a co-author of the study the quakes are close to a magnitude of 5 on the Richter scale and this is a big earthquake.
Commonly earthquakes are caused by faults in the tectonic plates but these earthquakes are unique because they are caused by massive movements of ice. Compared to the early 90’s Nettles reports that scientists are detecting seven times more earthquakes coming from Greenland and the rate is increasing probably due to the fact that ice sheet has begun to lose more mass from the calving of icebergs at the front end of glaciers.
To have a better understanding behind the forces working behind the glacial earthquakes, scientists have put GPS instruments atop one of the Greenland’s fast moving glaciers, the Helheim Glacier situated in the southeastern part of Greenland , across the Denmark strait from Iceland. The team also monitored the glacier’s calving front where the ice meets the water with the aid of camera and at the same time used global seismic data to track earthquake occurrences.
In other terms the mass which we are talking here is gigantic. A typical big iceberg breaking off Helheim could be 4 kilometers in length and it is no wonder a body this size can shake Earth when it moves and when it throws its weight behind another solid object leading to iceberg calving.