2010 Chile Earthquake Triggered Icequakes in Antarctica
By Indrani Bhattacharyya | August 12, 2014 1:35 PM EST
Seismic events keep taking place in Antarctica. Sections of the frozen desert may go through hundreds of micro-earthquakes roughly within an hour because of ice deformation.
Some researchers define them as ice-quakes.
The MV Akademik Shokalskiy is pictured stranded in ice in Antarctica, December 29, 2013. Fog and heavy snow mean the 74 passengers on the Russian ship stranded in Antarctica for over a week are likely to ring in the New Year trapped in the ice, as a rescue helicopter on a nearby Chinese ship waits for the weather to clear. The helicopter on board the Snow Dragon will be used after an Australian icebreaker failed to reach the trapped Akademik Shokalskiy, the Australian Maritime Safety Authority said. The Russian ship left New Zealand on November 28 on a privately funded expedition to commemorate the 100th anniversary of an Antarctic journey led by famed Australian explorer Douglas Mawson.
According to the report by Science Daily, in March of 2010, the ice sheets of Antarctica went through unusual vibrations because the 8.8-magnitude huge Chilean earthquake which happened as far as 3000 miles away.
A new study from Georgia Institute of Technology which got published in Nature Geoscience reported that Antarctica's frozen ground is sensitive to seismic waves from distant earthquakes.
In order to investigate the impact of the quake on Antarctica, the team looked at the seismic data from 42 stations in the six hours before and after the event.
As explained by Science Daily, lead author Zhigang Peng, an associate professor in the School of Earth and Atmospheric Sciences, said "We interpret these events as small icequakes, most of which were triggered during or immediately after the passing of long-period Rayleigh waves generated from the Chilean main shock."
Peng also explained that the newly found ice-quakes respond only to volumetric deformation.
Some of these ice-quakes were quick and got over in less than one second while others were of long duration that stayed up to 10 seconds.
They took place in different parts of the continent, including seismic stations along the coast and near the South Pole.
Scientists found the clearest indication of induced high-frequency signals at station HOWD which was located near the northwest corner of the Ellsworth Mountains.
According to Peng it was difficult to determine the source locations of the ice-quakes because of the lack of extensive seismic network coverage in Antarctica.
But he felt that as some of the ice-quakes themselves are capable of creating surface waves, they are most likely formed very close to the ice surface.
To contact the editor, e-mail: