Seismic events aren’t rare on Antarctica, where sections of the frozen desert can experience hundreds of micro-earthquakes an hour due to ice deformation. Some scientists call them icequakes.
But in March 2010, the ice sheets in Antarctica vibrated a bit more than usual because of something more than 3,000 miles away: the 8.8-magnitude Chilean earthquake. A study published in the journal Nature Geoscience is the first to indicate that Antarctica’s frozen ground is sensitive to seismic waves from distant earthquakes.
To study the quake’s impact on Antarctica, a team from Georgia Tech looked at seismic data from 42 stations in the six hours before and after the 3:34 a.m. event. The researchers used the same technology that allowed them to “hear” the seismic response to the devastating 2011 magnitude 9 Japan earthquake as it rumbled through the Earth. They removed the longer-period signals as the seismic waves spread from the distant epicenter to identify high-frequency signals from nearby sources. Nearly 30 percent of the stations showed clear evidence of high-frequency seismic signals as the surface wave arrived on Antarctica.
“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,” said Zhigang Peng, an associate professor in Georgia Tech’s School of Earth and Atmospheric Sciences who led the study.