January 15, 2012 – Two Earthquakes Struck the South Shetland Islands: Two quakes struck the South Shetland Islands today, only 41 minutes apart. The first was a 6.5 magnitude quake that hit at 9:40AM (local time) and the second was a 6.2 magnitude tremor at 10:21AM.
The South Shetland Islands are a group of Antarctic islands, lying about 120 kilometers (75 miles) north of the Antarctic Peninsula.
The islands have been claimed by the United Kingdom since 1908 and have been part of the British Antarctic Territory since 1962. They are also claimed by the governments of Chile (since 1940, as part of the Antarctica Chilean Province) and by Argentina (since 1943, as part of Argentine Antarctica, Tierra del Fuego Province).
Earthquakes in this region are very rare. Of the 350 quakes >= 7.0 magnitude, over the last 39 years; only three occurred near Antarctica. The last hit this region on August 4, 2003 and was rated a powerful 7.6 magnitude. Argentina saw only one quake during that same time period. It occurred on November 23, 1977 and was a 7.4 magnitude quake that killed 70, injured 300 and did $80 million in damages.
The first quake (6.5M) was 288 miles west of Coronation Island, in the South Orkney Islands; 632 miles south of Stanley, in the Falkland Islands; and 781 miles southeast of Punta Arenas, Chile. The second quake (6.2M) occurred 41 minutes later, about 13 miles to the northwest.
Since Chile lies along the eastern edge of the “Ring of Fire,” it is very earthquake prone; with 15 quakes >= 7.0M over the last 39 years.
Note 1: The USGS (United States Geological Survey) originally reported a third earthquake, of 6.6 magnitude, in the same area as the two described above. However, this event was deleted by the USGS at 9:15AM PST.
Note 2: The USGS reported a fourth earthquake, of 6.2 magnitude, in the same area as the two detailed above; at 11:51AM PST. However, this event was deleted by the USGS at 12:11PM. What’s going on at the USGS?
The Master of Disaster