Deepest Erupting Submarine Volcano
Posted by feww on December 18, 2009
Erupting West Mata Volcano shown in newly released video, images
Researchers have recorded the deepest erupting volcano known, West Mata Volcano, describing high-definition video of the submarine eruption as “spectacular.”
An explosion at the West Mata Volcano throws ash and rock, with molten lava glowing below. Credit NOAA/NSF
“For the first time we have been able to examine, up close, the way ocean islands and submarine volcanoes are born,” said Barbara Ransom, program director in NSF’s Division of Ocean Sciences. “The unusual primitive compositions of the West Mata eruption lavas have much to tell us.”
Bubbles of gas-rich magma burst, spewing lava fragments into the water.
A sequence of closer views of the eruption, with bright flashes of hot magma.
Credit: National Science Foundation and National Oceanic and Atmospheric Administration
The volcanic eruption, discovered in May, is nearly 4,000 feet below the surface of the Pacific Ocean, in an area bounded by Fiji, Tonga and Samoa.
Summit of West Mata Volcano, shown in red, is nearly a mile below the ocean surface (1,165 meters / 3,882 feet), and the base, shown in blue, descends to nearly two miles (3,000 meters / 9,842 feet) deep. Eruptions occurred at several places along the summit, in an area about 100 yards. The volcano has a six-mile-long rift zone running along its spine in a SW/NE orientation. Credit: NOAA. Click image to enlarge.
West Mata Volcano (white ellipse on bathymetric map) is not the largest volcano in the northeast Lau Basin, but appears to be the most active. Map represents the area visited and mapped on two recent expeditions. Summit of West Mata Volcano is nearly one mile deep, the base is nearly two miles deep. Tonga Trench (north and east of the expedition area) is nearly seven miles deep. Credit NOAA. Click image to enlarge.
West Mata Volcano, in the Lau Basin, is located in the southwest Pacific, within an area bounded by Samoa, Tonga and Fiji (the black areas on the map, which are the only areas above water). Area is home to many submarine volcanoes. Credit NOAA. Click image to enlarge.
“We found a type of lava never before seen erupting from an active volcano, and for the first time observed molten lava flowing across the deep-ocean seafloor,” said the expedition’s chief scientist Joseph Resing, a chemical oceanographer at the University of Washington.
“It was an underwater Fourth of July, a spectacular display of fireworks nearly 4,000 feet deep,” said co-chief scientist Bob Embley, a marine geologist at NOAA’s Pacific Marine Environmental Laboratory in Newport, Ore.
“Since the water pressure at that depth suppresses the violence of the volcano’s explosions, we could get an underwater robot within feet of the active eruption. On land, or even in shallow water, you could never hope to get that close and see such great detail.”
An eruptive blast at West Mata Volcano, with superheated pillow lava flowing downslope. Credit: NSF/NOAA
Imagery includes large molten lava bubbles three feet across bursting into cold seawater, glowing red vents exploding lava into the sea, and the first-observed advance of lava flows across the deep-ocean floor.
Sounds of the eruption were recorded by a hydrophone and later matched with the video footage.
Expedition scientists released the video and discussed their observations at a Dec. 17 news conference at the American Geophysical Union (AGU)’s annual fall meeting in San Francisco.
The West Mata Volcano is producing boninite lavas, believed to be among the hottest on Earth in modern times, and a type seen before only on extinct volcanoes more than one million years old.
The orange glow of magma in an eruptive area the length of a football field along the summit. Credit: NSF/NOAA
A University of Hawaii geochemist believes that the active boninite eruption provides a unique opportunity to study magma formation at volcanoes, and to learn more about how Earth recycles material where one tectonic plate is subducted under another.
Water from the volcano is very acidic, with some samples collected directly above the eruption, the scientists said, as acidic as battery acid or stomach acid.
Shrimp congregate near the summit of West Mata Volcano, withstanding hot, acid waters. Credit: NSF/NOAA
A microbiologist at the Marine Biological Laboratory, found diverse microbes even in such extreme conditions.
A biologist at the Woods Hole Oceanographic Institution (WHOI), found that shrimp were the only animals thriving in the acidic vent water near the eruption. Shank is analyzing shrimp DNA to determine whether they are the same species as those found at seamounts more than 3,000 miles away.
The scientists believe that 80 percent of eruptive activity on Earth takes place in the ocean, and that most volcanoes are in the deep sea.
Superheated molten lava, about 2200 degrees Fahrenheit, is about to explode into the water. Credit: NSF/NOAA
Further study of active deep-ocean eruptions will provide a better understanding of oceanic cycles of carbon dioxide and sulfur gases, how heat and matter are transferred from the interior of the Earth to its surface, and how life adapts to some of the harshest conditions on Earth.
The science team worked aboard the University of Washington’s research vessel Thomas Thompson, and deployed Jason, a remotely-operated vehicle owned by WHOI.
A pillow lava tube extends downslope in an area about three feet across. Credit: NSF/NOAA
Jason collected samples using its manipulator arms, and obtained imagery using a prototype still and HD imaging system developed and operated by the Advanced Imaging and Visualization Lab at WHOI.
Other expedition participants were affiliated with Oregon State University, Monterey Bay Aquarium Research Institute, Western Washington University, Portland State University, Harvard University, the University of Tulsa, California State University’s Moss Landing Marine Laboratory, the University of California Santa Cruz and Lamont Doherty Earth Observatory.