Undersea quake hits South Sandwich Islands

An earthquake with a preliminary magnitude of 7.3 was registered off the South Sandwich Islands in the South Atlantic Ocean, the US Geological Survey reported today.

The quake struck at 5.10am local time (6.10am Irish time), and was centred six miles (10km) under the seabed, some 215 miles (345km) south-east of Bristol Island of the South Georgia and South Sandwich Islands – an overseas territory of Britain also claimed by Argentina – the survey said on its Web site.

The Japanese Meteorological Agency reported the same earthquake with magnitude 7.5. The agency said it did not have any information about whether the quake had triggered a tsunami, according to spokesman Kana Akiyama.

Underwater quakes at shallow depths can cause tsunami waves, which are often barely noticeable in the ocean but can rise to great heights once they arrive at shore.

In December 2004, a magnitude-9 quake caused tsunami waves in the Indian Ocean that swept across 11 countries, leaving at least 216,000 people dead or missing.

South Georgia, formerly a whaling station, is now a permanent station run by scientists from the British Antarctic Survey. The South Sandwich Islands to the south of South Georgia are uninhabited.

The islands are administered from the Falkland Islands, another British overseas territory some 620 miles (1,000km) away.