Small earthquakes commonly shake East Antarctica, suggesting the region is not as quiet as researchers previously thought, a new study published in the journal Nature Geoscience reports.
This finding comes from scientists at Drexel Univeristy, who detected the small earthquakes for the first time. Not only are the movements unique, but they also help add to the geological mystery of the region.
Researchers first detected the odd motions by analyzing data gathered in 2009 by a network of seismic sensors deployed across the area. That was the first time researchers collected any seismic data from East Antarctica.
From there, the team buried sensors deep within the ice to make sure they only picked up seismic activity and did not trigger off of false signals like strong wind. After spending some time eliminating such possibilities, scientists discovered that 27 earthquakes shook the region during the course of a year.
While none of them were particularly large — all under a 4 — they did register. That means recent advancements give a better picture of the continent.
“Ultimately, the lack of recorded seismicity wasn’t due to a lack of events but a lack of instruments close enough to record the events,” explained lead author Amanda Lough, a professor at Drexel University’s College of Arts and Sciences, according to Phys.org.
An earthquake once every two weeks is a lot of seismic activity for an area previously thought of as almost completely still. In fact, while calculations show that East Antarctica should have less earthquakes than the Canadian Shield, the two regions are similar.
Researchers are not sure what mechanisms trigger the earthquakes, nor do they know why they are hard to detect on the surface. Even so, this new study is a significant step towards understanding such mechanisms and getting a better idea of geological activity that drives the unique region.
“To get winter data in Antarctica before, we had a couple of permanent stations but the interior wasn’t covered at all,” said Lough, according to Newsweek. “It was this huge step forward.”