A 7.4-magnitude quake shook the southern Atlantic Ocean early Friday, the US Geological Survey said, with an epicenter 195 miles (316 kilometers) from islands hosting a British Antarctic research station.

There was no immediate tsunami warning.

The quake struck at 5:32 am local time (0732 GMT) at a depth of 10 kilometers. It was centered east-southeast of the British administered South Georgia and South Sandwich Islands.