Earthquakes, Plate Tectonics, Earth Structure - 10 of 11
Earthquakes, Plate Tectonics, Earth Structure FAQs - 11 Found
Earthquakes do occur occasionally in Antarctica, but not very often. There have been some big earthquakes--including one magnitude 8--in the Balleny Islands. The boundary between the Scotia Plate and the Antarctic Plate just grazes the north tip of the Antarctic Peninsula (again, look "northwest" from the Pole toward South America). There is also a hint of a line of seismicity off the west coast of the Antarctic Peninsula and some activity in the Kerguelen Plateau (in the Indian Ocean "northeast" from the Pole). The Kerguelen Plateau is within the Antarctic Plate but it is not part of the Antarctic Continent. As with the interior area of all tectonic plates, earthquakes can and do occur in Antarctica, but they are much less frequent than quakes on the plate boundaries.
Another reason why there are fewer quakes located in Antarctica than within other plates such as Australia or North America is because smaller quakes are much more likely to go undetected in Antarctica because there are very few seismograph stations. There are only 19 operating seismograph stations (as of 2005 )in all of the continent of Antarctica, and only one of them, at the Amundsen-Scott South Pole Station, is in the interior of the continent. By comparison, there are 42 stations within the State of New Mexico. The closest seismograph station to the one at South Pole is 1350 km or about 840 miles. That's a big area to hide little earthquakes in!
Finally, the interior of Antarctica has icequakes which, although they are much smaller, are perhaps more frequent than earthquakes. The icequakes are similar to earthquakes, but occur within the ice sheet itself instead of the land underneath the ice. Some of our polar observers have told us they can hear the icequakes and see them on the South Pole seismograph station, but they are much too small to be seen on enough stations to obtain a location.