Do earthquakes occur in Antarctica?
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 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.
Can the position of the moon or the planets affect seismicity? Are there more earthquakes in the morning/in the evening/at a certain time of the month?
When it's summer in the Antarctic, winter is in the northern hemisphere, USGS scientific teams along with many other international researchers are on the Antarctic ice studying unprecedented changes in remote polar regions.
According to the U.S. Geological Survey (USGS), 2004 was the deadliest year for earthquakes since the Renaissance Age, making it the second most fatal in recorded history, with more than 275,950 deaths reported from the magnitude 9.0 earthquake and subsequent tsunami that hit the Indian Ocean on Dec. 26.
A typical landscape in the Dry Valleys of Antarctica (January 2015).
Mount Erebus in background. Little Razorback (left) and Big Razorback (right) islands are sites of seal colonies. Images were obtained under NMFS Permit No: 1032-1917.
Mount Erebus in background of Inaccessible Island. Images were obtained under NMFS Permit No: 1032-1917.
Penguins huddle together near Erebus Bay, Antarctica. Images were obtained under NMFS Permit No: 1032-1917.
In our second Earth Science Week installment, we talk with scientist Richie Williams about the USGS's amazing new satellite imagery of Antarctica as well as what's going on with ice on the southernmost continent.