Showing posts with label MOLTEN ROCK. Show all posts
Showing posts with label MOLTEN ROCK. Show all posts

Monday, April 27, 2015

MAGMA DISCOVERED BENEATH YELLOWSTONE SUPERVOLCANO

FROM:  NATIONAL SCIENCE FOUNDATION
Yellowstone magma discovery
NSF-funded seismologists at the University of Utah discover magma hidden beneath Yellowstone's supervolcano

A team of University of Utah seismologists has discovered a reservoir of hot, partly molten rock hidden 12 to 28 miles beneath Yellowstone's supervolcano--enough to fill the 1000 cubic-mile-Grand Canyon more than 11 times. The pool is over four times larger than a shallower, long-known magma chamber.

The National Science Foundation (NSF)-funded team, developed a new technique that uses both local and distant earthquake data from the University of Utah Seismograph Stations and the NSF-funded EarthScope array of seismometers. The combined data resulted in a better, deeper and more complete image of the system. The newly discovered reservoir carries hot and partly molten rock upward from the top of Yellowstone's hotspot plume--about 40 miles below the surface.

Yellowstone's plumbing system is no larger or closer to erupting than before, scientists are just seeing more of it than ever before. Yellowstone is among the world's largest supervolcanoes, with frequent earthquakes. The team believes these new models help us gain a better understanding of Yellowstone's plumbing system, and may lead to improved estimates of the potential future seismic and volcanic hazards.

-- Dena Headlee,
Investigators
Fan-Chi Lin
Related Institutions/Organizations
University of Utah

Friday, March 22, 2013

LIQUIFIED MOLTEN ROCK DISCOVERED IN EARTH'S MANTLE

Lava fountain at Kilauea in Hawaii.  Credit:  Wikimedia Commons/USGS.
FROM: NATIONAL SCIENCE FOUNDATION
Scientists Discover Layer of Liquified Molten Rock in Earth's Mantle

Scientists have discovered a layer of liquified molten rock in Earth's mantle that may be responsible for the sliding motions of the planet's massive tectonic plates.

The finding may carry far-reaching implications, from understanding basic geologic functions of the planet to new insights into volcanism and earthquakes.

The research was funded by the National Science Foundation (NSF), and is reported in this week's issue of the journal Nature by Samer Naif, Kerry Key, and Steven Constable of the Scripps Institution of Oceanography (SIO), and Rob Evans of the Woods Hole Oceanographic Institution.

"This new image greatly enhances our understanding of the role that fluids, both seawater and deep subsurface melts, play in controlling tectonic and volcanic processes," said Bil Haq, program director in NSF's Division of Ocean Sciences, which funded the work through the NSF Directorate for Geosciences' MARGINS (now GeoPRISMS) Program.

The scientists discovered the magma layer at the Middle America trench off Nicaragua's shores.

Using advanced seafloor electromagnetic imaging technology pioneered at SIO, the scientists imaged a 25-kilometer- (15.5-mile-) thick layer of partially melted mantle rock below the edge of the Cocos plate where it moves beneath Central America.

The new images of magma were captured during a 2010 expedition aboard the research vessel Melville.

After deploying a vast array of seafloor instruments that recorded natural electromagnetic signals to map features of the crust and mantle, the scientists realized they had found magma in a surprising place.

"This was completely unexpected," said Key. "We went out looking to get an idea of how fluids are interacting with plate subduction, but we discovered a melt layer we weren't expecting to find."

For decades scientists have debated the forces that allow the planet's tectonic plates to slide across the Earth's mantle.

Studies have shown that dissolved water in mantle minerals results in a more ductile mantle that would facilitate tectonic plate motions, but for many years clear images and data required to confirm or deny this idea were lacking.

"Our data tell us that water can't accommodate the features we are seeing," said Naif. "The information from the new images confirms the idea that there needs to be some amount of melt in the upper mantle. That's what's creating this ductile behavior for plates to slide."

The marine electromagnetic technology employed in the study was originated by Charles "Chip" Cox, an emeritus oceanographer at SIO, and in recent years further advanced by Constable and Key.

They have been working with the energy industry to apply this technology to map offshore oil and gas reservoirs.

The researchers say their results will help geologists better understand the structure of the tectonic plate boundary and how that affects earthquakes and volcanism.

"One of the longer-term implications of our results is that we are going to understand more about the plate boundary, which could lead to a better understanding of earthquakes," said Key.

The researchers are now trying to find the source that supplies the magma in the newly discovered layer.

The Seafloor Electromagnetic Methods Consortium at SIO also supported the research.

-NSF-

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