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Archive for the ‘Submarine eruption’ Category

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

Download as Quicktime: Video 1 [Web resolution] (Credit: NOAA and NSF)
Download as Quicktime: Video 2 [Web resolution] (Credit: NOAA and NSF)

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.

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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.

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Posted in boninite lavas, extinct volcanoes, Pacific Ocean, Submarine eruption, West Mata Volcano | Tagged: , , , , | 3 Comments »

Tonga’s Metis Shoal may be erupting

Posted by feww on February 3, 2009

Metis Shoal Submarine Volcano May Be Erupting

1. FEWW seismic analysis of Tonga Islands region in south Pacific Ocean (SPO) indicate that Metis Shoal, a submarine volcano located midway between the islands of Kao and Late (about 50 km NNE of Kao), may be about to erupt, or is currently undergoing a period of unrest.

2. Metis Shoal’s last known eruption occurred in 1995, which produced an island with a diameter of about 300 m and a height of 43 m after a solid lava dome was formed above the surface of water in SPO.

3. Since 1851 some 8 episodes of unrest have been recorded. In three, possibly five, of those occasions new islands were created (1858, 1967-68, 1979, 1995).

Metis Shoal

  • Country:  Tonga
  • Region:  Tonga Islands, SPO
  • Volcano Type:  Submarine volcano
  • Last Known Eruption:  1995
  • Summit Elevation:  43 m asl
  • Latitude: 19.18°S   19°11’0″S
  • Longitude:  174.87°W   174°52’0″W

4. Metis Shoal, a submarine volcano midway between the islands of Kao and Late, has produced a series of ephemeral islands since the first confirmed activity in the mid-19th century. An island, perhaps not in eruption, was reported in 1781 and subsequently was eroded away. During periods of inactivity following 20th-century eruptions, waves have been observed to break on rocky reefs or sandy banks with depths of 10 m or less. Dacitic tuff cones formed during the first 20th-century eruptions in 1967 and 1979 were soon eroded beneath the sea surface. An eruption in 1995 produced an island with a diameter of 280 m and a height of 43 m following growth of a lava dome above the surface. [Caption: GVP]


5. Waves break over Metis Shoal on February 19, 1968, more than a month after the end of a submarine eruption that began in December 1967 and produced an ephemeral island. Metis Shoal has produced a series of small islands during eruptions observed since the mid-19th century. Most recently, an eruption in 1995 produced a lava dome that built up to 43 m above sea level. Photo by Charles Lundquist, 1968 (Smithsonian Astrophysical Observatory). Caption: GVP


6. Map of the Tonga Islands, showing the island groups and location of Metis Shoal, which re-emerged as an island in June 1995. Source: GVP

Other Photos of Metis Shoal


7. Metis Shoal, sea level view. Source: MTU


8. Metis shoal, aerial view. Source: MTU


9. Metis Shoal aerial photo dated December 7,  2006. Source: GVP

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Content of this post: 424 words, 9 paras/captions, 5 images, 1 list w/9 bullets

Posted in fumarolic activity, Submarine eruption, tephra, volcanic unrest, volcanoes | Tagged: , , , , | 7 Comments »