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Erupting undersea volcano filmed

Scientists have recorded the deepest erupting undersea volcano ever seen, some 1,200 metres beneath the Pacific Ocean.

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A submersible robot witnessed the eruption in May during an underwater expedition near Samoa, and the high-definition videos were presented today at a geophysics conference in San Francisco.

Scientists hope the images, data and samples obtained during the mission will shed new light on how the earth’s crust was formed.

The research could also help explain how some sea creatures survive and thrive in extreme environments and how the earth behaves when tectonic plates collide.

“It was an underwater Fourth of July,” said Bob Embley, a marine geologist for the National Oceanic and Atmospheric Administration, in a news release.

“Since the water pressure at that depth suppresses the violence of the volcano’s explosions, we could get the underwater robot within feet of the active eruption.”

The eruption was a spectacular sight. Video showed bright-red magma bubbles releasing a smoke-like cloud of sulphur, then freezing almost instantly in the cold sea water, causing black rock to sink to the to the sea floor.

The submersible hovered near the blasts, its robotic arm reaching into the lava to collect samples.

Eighty percent of the earth’s volcanic activity occurs in the sea, making scientific observation difficult.

Researchers from NOAA and the National Science Foundation had studied deep-sea volcanoes extensively but never witnessed an eruption.

The mission’s chief scientist, Joseph Resing, last year detected volcanic material in the water in the area and realised it was erupting.

In May, the researchers travelled to the area and sunk the submersible robot, called Jason, hoping to make scientific history.

Scientists said the water around the volcano was more acidic than battery acid, but that shrimp and certain microbes seemed able to thrive.

Biologists will study these creatures to see if they are unique to this volcanic environment.

Researchers will also continue to monitor the changing West Mata volcano, about 250 kilometres southwest of Samoa.

Earth and ocean scientists also said the eruption allowed them to see the real-time creation of a rock called boninite, which had previously been found only in samples a million or more years old.