Scientists map volcanic plume under Yellowstone

Apr 15, 2011 By MATT VOLZ , Associated Press
Aerial view showing faults associated with the northeastern side of the Yellowstone caldera. Image: U.S. Geological Survey

Scientists using electric and magnetic sensors have mapped the size and composition of a vast plume of hot rock and briny fluid down to 200 miles below Yellowstone National Park's surface, according to a new study soon to be published.

The so-called "geoelectric" imaging of a plume to this extent is a first, giving researchers a clearer picture of the material that feeds Yellowstone's volcanic features, said Robert B. Smith, the study's co-author, a University of Utah professor emeritus and a coordinating scientist of the Yellowstone Volcano Observatory.

The information will help scientists better understand the evolution of these hot spots that are an integral part of continental drift and are active in 20 places around the world from Hawaii to Iceland, he said.

"This is the first time that an electrical image has been made of a plume anywhere in the world, period," Smith said. "We're getting much more information on the composition and evolution of the earth."

The plume is made up of solid rock, partly molten rocks and briny fluid that conducts electricity like seawater, said Smith and principal author Michael Zhdanov, a University of Utah geophysics professor. The plume rises from the earth's depths at a 40-degree angle and extends 400 miles from east to west, the data found. The image of the plume reaches a depth of 200 miles, the limit of the technology.

A previous study by Smith using seismic waves measured the plume's depth to at least 410 miles below the Montana-Idaho border.

The study will be published in within the next few weeks, according to the American Geophysical Union.

The new data, which measured the plume's to create the image, supplements Smith's that gave scientists their first detailed look at the plume in 2009. Both seismic and electrical conductivity are imaging technologies that reveal different things.

Together, the data reveal a plume that is larger and contains more brine and fluid than previously believed.

"All this is very important to better understand the physics of this plume," Zhdanov said. "We are just learning. It's a very new phenomenon and now we've got another tool to get an image and better understanding of the composition and geographical shape."

That tool may help lead one day to developing a way to better forecast eruptions and other volcanic activity, he said.

Derek Schutt, an assistant professor at Colorado State University, said others have used the geoelectric technology but not to these proportions. The technology is a useful supplement to seismic measurements and will lead to a better understanding of how the earth is forming, he said.

"I think what this will be particularly useful for is we can understand much better the magma distribution of what's under Yellowstone," he said.

The research says nothing about the chance for a large eruption happening at Yellowstone, which draws millions each year to see its bubbling pots and spouting geysers. Yellowstone's caldera, a 37-by-25-mile volcanic feature at the center of the park, has erupted three times since the North American continent drifted over the hot spot. The last eruption was 642,000 years ago.

The plume stops rising about 60 miles below the surface. Some of that melted rock then leaks up, possibly through a series of rock fractures, to a chamber about five miles below the surface of the Yellowstone caldera, Smith said. That magma chamber feeds the volcanic activity on the surface.

If enough of the plume breaks off and rises to the chamber, an eruption could happen. But that accumulation happens very slowly over thousands of years and there is no indication of when an eruption could occur, Zhdanov said.

Explore further: Images released of shipwreck in San Francisco Bay

4.8 /5 (8 votes)
add to favorites email to friend print save as pdf

Related Stories

Yellowstone's plumbing exposed

Dec 14, 2009

( -- The most detailed seismic images yet published of the plumbing that feeds the Yellowstone supervolcano shows a plume of hot and molten rock rising at an angle from the northwest at a depth ...

Terra Satellite Helps Measure Iceland Volcanic Plume

Apr 21, 2010

( -- NASA's Terra satellite flew directly over Iceland on April 19, 2010, allowing its Multi-angle Imaging SpectroRadiometer (MISR) instrument to capture a series of images of the Eyjafjallajökull ...

Recommended for you

NASA sees last vestiges of Tropical Depression Jack

16 hours ago

Tropical Cyclone Jack had weakened to a tropical depression when NASA and JAXA's Tropical Rainfall Measuring Mission (TRMM) satellite passed above on April 22, 2014 at 1120 UTC/7:20 a.m. EDT.

New discovery helps solve mystery source of African lava

20 hours ago

Floods of molten lava may sound like the stuff of apocalyptic theorists, but history is littered with evidence of such past events where vast lava outpourings originating deep in the Earth accompany the breakup ...

Climate change likely to make Everest even riskier

20 hours ago

Climbing to the roof of the world is becoming less predictable and possibly more dangerous, scientists say, as climate change brings warmer temperatures that may eat through the ice and snow on Mount Everest.

User comments : 0

More news stories

On global warming, settled science and George Brandis

The Australian Attorney General, Senator George Brandis is no stranger to controversy. His statement in parliament that "people do have a right to be bigots" rapidly gained him notoriety, and it isn't hard to understand why ...

When things get glassy, molecules go fractal

Colorful church windows, beads on a necklace and many of our favorite plastics share something in common—they all belong to a state of matter known as glasses. School children learn the difference between ...

FCC to propose pay-for-priority Internet standards

The Federal Communications Commission is set to propose new open Internet rules that would allow content companies to pay for faster delivery over the so-called "last mile" connection to people's homes.