Icequakes in Antarctica Linked to 2010 Chile Earthquake
The 8.8-magnitude earthquake that shook Chile in 2010 also rattled ice in Antarctica, a new study reveals.
Georgia Institute of Technology researchers, who conducted the latest study, show that distant seismic activity also affects ice in the frozen continent.
The 2010 earthquake occurred about 3,000 miles away from Antarctica. At least 300 people were killed and some two million people were affected by the quake.
In the current study, the researchers obtained seismic data from 42 stations in the six hours before and after the 3:34 a.m. event.
Around 30 percent of the stations studied showed clear evidence of high-frequency seismic signals due to the surface wave that travelled from Chile to Antarctica, the researchers have found.
"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 mainshock," said Zhigang Peng, an associate professor in the School of Earth and Atmospheric Sciences who led the study.
The regions that experience high seismic activity due to movement of tectonic movements usually have micro-earthquakes caused by both Love and Rayleigh-type surface waves. The icequakes in this study are different from the micro-earthquakes seen in other places, scientists said.
According to the researchers, icequakes only respond to volumetric deformities unlike the micro-earthquakes, which respond to both shearing and volumetric deformation.
"Such differences may be subtle, but they tell us that the mechanism of these triggered icequakes and small earthquakes are different," Peng added in news release. "One is more like cracking, while the other is like a shear slip event. It's similar to two hands passing each other."
Limited seismic network coverage in Antarctica makes it difficult to study icequakes in the region, Peng added.
The study is published in the journal Nature Geoscience.