/ 23 November 2005

Rare volcanic eruption adds to island

A rare volcanic eruption is expanding the size of Montagu Island in the uninhabited South Sandwich Islands chain, a remote British territory in the southern Atlantic Ocean, scientists said on Wednesday.

Researchers from the British Antarctic Survey and the Hawaii Institute of Geophysics said new satellite images show that Montagu Island has grown by 20,23ha in the past month alone.

A large and fast flow of lava is pouring into the sea like a large waterfall, the scientists said.

”Red-hot lava has formed a molten river 90m wide that is moving fast, possibly several metres per second, and extending the shoreline on the north side of the island,” said John Smellie, of the British Antarctic Survey.

”This event is special because Montagu Island is mostly ice-covered and it’s very rare that we get to make direct observations of eruptions under ice sheets.”

Smellie said he spends much of his time studying Antarctic rock formations to find out how past eruptions affected the growth and retreat of ice sheets over the past 30-million years, adding: ”This opportunity to monitor a live eruption and see how it affects ice cover is priceless.”

Researchers believed that volcanic activity on Montagu Island, which started in 2001, was winding down until they were alerted to the new satellite pictures showing the large, fast-moving lava flow. It is the first eruption observed on the island.

The 11 South Sandwich Islands form an arc on a volcanic fault line. They are important to researchers because of their remoteness from any continental landmass, making the lavas pristine, or unaffected by continental contamination. This reveals how the Earth’s crust was formed and how it will evolve.

The South Sandwich Islands are about 2 400km east-southeast of the Falkland Islands. — Sapa-AP