Scientists say the seismic activity in Antarctica since the end of August is unusual.

Scientists say the seismic activity in Antarctica since the end of August is unusual.
Scientists at the University of Chile record the spike in seismic activity - including one strong quake of magnitude 6.

More than 30,000 tremors have rocked Antarctica since the end of August, according to new research.

Scientists at the University of Chile recorded the spike in seismic activity while studying the remote icy continent.

The university's National Seismological Centre said the small quakes - including one stronger one of magnitude 6 - were detected in the Bransfield Strait.

This is a 60-mile wide ocean channel between the South Shetland Islands and the Antarctic Peninsula.

Several tectonic plates and microplates meet near the strait, leading to frequent rumbling - but the past three months have been unusual, researchers said.

"Most of the seismicity is concentrated at the beginning of the sequence, mainly during the month of September, with more than a thousand earthquakes a day," the centre said.

The tremors have become so frequent that the strait itself, once increasing in width at a rate of about 7 or 8mm (0.30 inches) a year is now expanding 15cm (6 inches) a year, it said.

"It's a 20-fold increase... which suggests that right this minute... the Shetland Islands are separating more quickly from the Antarctic peninsula," said Sergio Barrientos, the centre's director.