Giant lava lake found
Molten rock solidifies on contact with sea water
A lake of lava the size of a large city has been found on the floor of the Indian Ocean.
The expanse of once-molten rock is the largest yet discovered, measuring more than 10 kilometres (six miles) across.
The lake was detected by oceanographers from Southampton, UK, during a research cruise.
The frozen lava is evidence of a recent volcanic eruption at the boundary of the slowly separating African and Indian tectonic plates.
Dr Lindsay Parson, who is leading the expedition onboard RRS Charles Darwin, said: "A recent volcanic eruption has spilled about two cubic kilometres of lava over an area about the size of the City of London.
"Previously documented examples of lava lakes like these had only reached hundreds of metres across."
Research weblink
The scientists from Southampton Oceanography Centre are mapping the ocean floor using specialist sonar equipment and deep-sea video cameras.
Details of the findings are being posted on a website following the RRS Charles Darwin cruise.
"The rocks we see are glassy sheets and pillow lavas, where molten rock at more than a 1,000 degrees Celsius (1,832 Fahrenheit) has frozen in seconds as it met with sea water," said Dr Lindsay Parson.
"The heat from this eruption, which appears to have occurred over a relatively short period of time, is astonishing," said Dr Bramley Murton, who is in charge of sampling and rock analysis on the trip.
"It would amount to some 11 terawatts, roughly the equivalent of the output from 10,000 nuclear power stations," Dr Murton added.
All images are courtesy of the Southampton
Oceanography Centre
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