A magnitude-7.0 earthquake has struck in the South Atlantic, southeast of the disputed Falkland Islands, according to the U.S. Geological Survey (USGS).

It says the quake struck at 2-27 a.m. on Monday (0627 GMT), about 195 miles southeast of the Falklands’ capital, Stanley, and 545 miles east of Ushuaia, Argentina. The depth was a shallow 6.2 miles.

The Falklands are a British territory that is claimed by Argentina.

The USGS says the quake followed four others that all measured more than 5.0, over a two-hour period leading up to the big quake. It says such quakes are uncommon in the region. Only 15 quakes of more than magnitude 5.0 had been measured in the region in the previous 40 years.

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