Calving icebergs > Greenland earthquakes

How can an iceberg cause a major earthquake? Scientists now have a better understanding.

In Greenland immense icebergs 2 miles long and weighing a gigaton i.e. 1 billion tons are calving (breaking off) from the mainland's glaciers, falling into water. Shaped similarly to a piece of bread, they fall into water vertically then "capsize" i.e. fall over onto their sides. As they capsize, the upper part of the iceberg spins into the mainland glacier jamming it backward inland and reversing its normal forward seaward flow. As a secondary effect the falling iceberg also creates a tsunami. All this energy transfers through mainland glacier into the rocks below, causing an earthquake.

Giant earthquakes are shaking Greenland — and scientists just figured out the disturbing reason whyWashington Post
http://www.washingtonpost.com/news/energy-environment/wp/2015/06/25/giant-earthquakes-are-shaking-greenland-and-scientists-just-figured-out-the-disturbing-reason-why/?hpid=z4


"An island of ice breaking away from Greenland’s Petermann Glacier (in the center of the photo)  in the summer of 2010."
NASA satellite image