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Antarctica rocked by 30,000 tremors in 3 months, Chilean scientists say

作者:admin 2020-12-19

More than 30,000 tremors have rocked Antarctica since the end of August, according to the University of Chile, a spike in seismic activity that has intrigued researchers who study the remote, snowbound continent.

Antarctica rocked by 30,000 tremors in 3 months, Chilean scientists say

Crevasses near the grounding line of Pine Island Glacier, Antarctica Photo: VCG

Scientists with the university's National Seismological Center said the small quakes - including one stronger shake of magnitude 6 - were detected in the Bransfield Strait, a 96-kilometer-wide ocean channel between the South Shetland Islands and the Antarctic Peninsula. Several tectonic plates and microplates meet near the strait, leading to frequent rumbling, but the past three months have been unusual, according to the center.

"Most of the seismicity is concentrated at the beginning of the sequence, mainly during the month of September, with more than a thousand earthquakes a day," the center said.

The shakes have become so frequent that the strait itself, once increasing in width at a rate of about 7 or 8 millimeters a year is now expanding 15 centimeters a year, the center said.

"It's a 20-fold increase... which suggests that right this minute... the Shetland Islands are separating more quickly from the Antarctic Peninsula," said Sergio Barrientos, the center's director.

The peninsula is one of the fastest-warming places on Earth, and scientists closely monitor the changing climate's impact on its icebergs and glaciers. But climate scientist Raul Cordero of the University of Santiago said it was not yet clear how the tremors might be affecting the region's ice.

"There's no evidence that this kind of seismic activity... has significant effects on the stability of polar ice caps," Cordero told Reuters.

An earthquake with a magnitude of 5.9 jolted South Shetland Islands at 11:49 am local time on November 6, the US Geological Survey said.

The South Shetland Islands are a group of Antarctic islands lie about 120 kilometers north of the Antarctic Peninsula.
Newspaper headline: Antarctica rocked by 30,000 tremors in 3 months, scientists say

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