Sunday, December 28, 2008

"First Contact With Inner Earth": Drillers Strike Magma

http://uktv.co.uk/images/standarditem/EX1/1983.jpg



Magma is the liquid rock inside volcanoes. After it erupts from a volcano, magma is called lava.  Photo: uktv
A drilling crew recently cracked through rock layers deep beneath Hawaii and accidentally became the first humans known to have drilled into magma—the melted form of rock that sometimes erupts to the surface as lava—in its natural environment, scientists announced this week. "This is an unprecedented discovery," said Bruce Marsh, a volcanologist from Johns Hopkins University in Maryland, who will be studying the find.

Normally, he said, volcanologists have to do "postmortem studies" of long-solidified magmas or study active lava during volcanic eruptions.

But this time they'd found magma in its natural environment—something Marsh described as nearly as exciting as a paleontologist finding a dinosaur frolicking on a remote island.

"This is my Jurassic Park," he said at a meeting of the American Geophysical Union meeting in San Francisco.

First Contact

The find was made 1.5 miles (2.5 kilometers) underground during exploratory drilling for geothermal energy.

The crew hit something unusual during routine operations at the Puna Geothermal Venture, owned by Ormat Technologies, Inc., of Reno, Nevada.

When the workers tried to resume drilling, they discovered that magma had risen about 25 feet (8 meters) up the pipe they'd inserted.

The rock solidified into a clear glassy substance, apparently because it chilled quickly after hitting groundwater.

Scientists had long known that magma chambers must lie in the vicinity of the drill site.  ...

In addition, researchers found that the magma is made of dacite, a type of rock that's a precursor to granite, rather than the basalt that forms most of Hawaii.

"If we had hit basalt, that would not have been a big surprise," said William Teplow, a consulting geologist at U.S. Geothermal, Inc., who is assisting on the project.

Scientists have long believed that dacite can separate from basaltic magma to form granitic rocks. But they'd never expected to see the process in operation.

"This may be the first time that the generation of granite has actually been observed taking place in nature," Teplow said. "This is important because it's the process that differentiates the continental granitic crust from the more primitive oceanic basaltic crust." ...  It might even be possible to do experiments inside the magma.

"This could be the first magma observatory in the Earth," Marsh said. "This is a singular event of first contact with inner Earth, where magma lives."

Economical Power

With an estimated temperature of 1,900°F (1,050°C), the magma is also valuable as a high-quality heat source for geothermal energy production. ... - natgeo

Magma power is free clean energy. Let's do it.
To extract energy from magma resources requires drilling near or directly into a magma chamber and circulating water down the well in a convection- type system. California has two areas that may be magma resource sites: the Mono- Long Valley Caldera and Coso Hot Springs Known Geothermal Resource Areas. - energy.ca.gov

Long Valley Caldera cross section.jpgMagma power is the production of electricity from shallow magma bodies. Before magma becomes a practical source of power, many engineering problems must still be solved. When they are solved, the most likely site for the first magma power plant is Long Valley, California, USA. In this paper, we examine the greenhouse benefits from developing Long Valley. By generating magma power and by curtailing an equal amount of fossil power, we estimate the expected mass and the expected discounted value of reduced CO2 emissions. For both measures, the expected benefits seem to be substantial. - wiley

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