WORLD SCIENCE

"Long before it's in the papers"
August 03, 2010

Oct. 18, 2005
Courtesy Scripps Institution of Oceanography
and World Science staff

Scientists say they have rediscovered a lost geological treasure: the popping rocks of Guadalupe Island.

In 1960, oceanographer Dale Krause reported finding deep-sea volcanic rocks in waters off Mexico, near the island about 200 miles south of San Diego, Calif.

Guadalupe. (Courtesy National Oceanic and Atmospheric Administration, U.S.A.)

When brought to the surface, the rocks exploded “with a sharp snapping sound,” according to Krause, a researcher with the Scripps Institution of Oceanography in San Diego.

Since then, a few other sites, mostly along the Mid-Atlantic Ridge, have been reported with similar rocks. An attempt by the late Scripps Professor Harmon Craig to locate the original site in 1984 failed, largely because the location of the original discovery lacked the precision of today’s navigational technologies. 

A team of U.S. and Mexican geologists and students aboard the institution’s Revelle research vessel expedition explored the region early this month. The mission was to find the rocks and with them, unique information they could provide about Earth processes. 

On Oct. 9, the fifth day of the six-day trip, the researchers say they hit the jackpot along the flank of what the scientists are now calling Krause Volcano. “As soon as we took the rocks out of the water we could hear them popping, much like a firecracker,” said Barry Eakins of Scripps. “We knew this was a big find.” 

Eakins and Dana Vukajlovich, a Scripps graduate student, say the loud popping sounds are due to high concentrations of volcanic gases trapped in bubbles within the lava rocks. The gases explode when they escape the water pressure of the deep ocean floor, which keeps them confined within the rock.

The scientists say the rediscovery will give let them study these rare rocks in their Scripps laboratories and to compare them with popping rocks from the Mid-Atlantic Ridge. 

Vukajlovich said the rocks are important because the trapped volcanic gases such as carbon dioxide, water vapor, helium and argon should represent the concentrations of these gases in Earth’s mantle, the layer of Earth between the crust and the core. 

Eakins believes this will give researchers more information about the inventory of these gases within Earth and help them better understand the origin and history of the atmosphere. “These rocks will be the source of research for decades,” Eakins said. 

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