Rising Magma pushing up ground in Yellowstone
Pastor Dale Morgan
Rising Magma pushing up ground in Yellowstone*
* Story Highlights
* Molten rock flowing up at rate of three inches per year, study found
* No evidence that an eruption is imminent, study author says
* Yellowstone was once site of giant volcano
* Park is site of Old Faithful and hundreds of other geysers
WASHINGTON (AP) -- Yellowstone National Park, once the site of a giant
volcano, has begun swelling up, possibly because molten rock is
accumulating beneath the surface, scientists report.
Yellowstone's Great Fountain Basin spews in file photograph provided by
the National Parks Service.
But, "there is no evidence of an imminent volcanic eruption," said
Robert B. Smith, a professor of geophysics at the University of Utah.
Many giant volcanic craters around the world go up and down over decades
without erupting, he said.
Smith and colleagues report in Friday's issue of the journal Science
that the flow of the ancient Yellowstone crater has been moving upward
almost 3 inches per year for the past three years.
That is more than three times faster than ever observed since such
measurements began in 1923, the researchers said.
"Our best evidence is that the crustal magma chamber is filling with
molten rock," Smith said in a statement. "But we have no idea how long
this process goes on before there either is an eruption or the inflow of
molten rock stops and the caldera deflates again."
It's not unusual for ancient volcano sites like Yellowstone and Long
Valley, California, to rise and fall, according to the researchers.
The Yellowstone volcanic field was produced by what the researchers
described as a plume of hot and molten rock beginning at least 400 miles
beneath Earth's surface and rising to 30 miles underground, where it
widens to about 300 miles across.
Blobs of molten rock sometimes rise to refill the magma chamber beneath
Yellowstone.
The volcano at Yellowstone produced massive eruptions 2 million, 1.3
million and 642,000 years ago, all larger than the 1980 eruption of
Mount St. Helens.
Site of the famed Old Faithful and hundreds of other geysers,
Yellowstone sprawls across parts of Wyoming, Montana and Idaho.