An 8.8 magnitude earthquake in Chile on February 27, 2010 was so strong its impacts stretched to Antarctica. A new study shows that Antarctica experienced icequakes lasting anywhere between 1-10 seconds, even though the epicenter of the Chilean earthquake was located 2,900 miles north of Antarctica.
“Regular icequakes probably occur all the time in Antarctica and other polar regions,” said lead study author Zhigang Peng, a seismologist at the Georgia Institute of Technology in Atlanta. “What we found is that they occurred more during the seismic waves of the Maule event.”
As Peng noted above, icequakes occur regularly in Antarctica. They come following the formation of crevasses, water runoff or glaciers breaking away from bedrock.
This latest study, published in the journal Nature Geoscience, showed that just 12 of Antarctica’s 42 seismometers measured the 2010 earthquake. A pattern was noticed though. The opening or closing of small crevasses generated the icequakes. Areas predisposed to crevasses such as mountain ranges and fast-moving ice rivers were more likely to see icequakes.
“We think the crevasses are being activated by the surface waves from this big earthquake coming through, and that’s making the icequake,” said study co-author Jacob Walter.
The study also noted that it seemed only crevasses aligned toward the seismic waves were affected, but more research is needed to confirm this hypothesis.
How exactly does an earthquake halfway around the world affect Antarctica? The Rayleigh wave is responsible. It’s a surface wave that travels near the Earth’s surface. Think of it like a wave rolling on a lake after a boat goes by.
Also, this isn’t the first time Antarctica has felt the impacts of major earthquakes. Japan’s Tohoku tsunami in March 2011 broke off two massive icebergs from the Sulzberger Ice Shelf, more than 8,000 miles to the south.
Distance matters little when it comes to major earthquakes and their potential effects on Antarctica.