Sunday, 13 November 2016

Does Antarctica have earthquakes?

This just occurred to me today, during one of the many, many aftershocks following last night’s big earthquake just after midnight. I know they have volcanoes in Antarctica, but do they have earthquakes?

Well, they do have some. There was a magnitude 6.0 earthquake on 31 January 2016 that struck the area around the Balleny Islands. I’d never heard of the Balleny Islands, but they are a remote, uninhabited group of islands 2000 km south of NZ.

According to the US Geological Survey (USGS), “Earthquakes do occur occasionally in Antarctica, but not very often.” Or if they do occur, they may not be noticed, because there are very few seismograph stations for the size of the continent.

But they do have icequakes – I didn’t know that! Ice quakes vary in intensity, just like earthquakes do. They are vibrations in the glaciers and ice sheets, “similar to earthquakes, but [they] occur within the ice sheet itself instead of the land underneath the ice.”

And yes, there is a seismograph station at Scott Base. Good to know.

Ray Dibble monitoring Erebus seismograph
©Antarctica New Zealand Pictorial Collection, CC  licence

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