Magma chamber discovered in Hawaii

WASHINGTON - A geothermal power company drilling 1 1/2 miles deep on one of the Hawaiian Islands has for the first time encountered an undisturbed chamber of magma, or molten rock, scientists reported this week.

The 2,000-degree Fahrenheit material in the chamber is undergoing a complicated transformation that may give geologists the first real-time look at how the silicate-rich rock of continents is formed.

"This is Jurassic Park. This is first contact. Here we see this [continental] stuff being produced in its natural habitat," said Bruce Marsh, a geologist at Johns Hopkins University, who described the findings at a meeting of the American Geophysical Union in San Francisco.

The ocean floor and volcanic islands like Hawaii are made of basalt, a black rock that in its molten form is the "mother fluid" of the 4.5 billion-year-old Earth. How it gave rise to the silica-enriched rock that formed the continents 2.5 billion years ago is a crucial question in geology.

The geothermal company "recognized immediately that this was something very anomalous," said William Teplow, one of the two geologists at the plant.

The chamber, discovered in 2005, is described as a swollen pancake about the length of a football field and perhaps 50 feet thick. It was hit by chance.

The magma rose up about 20 feet into the drill hole before cooling into a glass-like substance. A part of the hole eventually collapsed, pinning the drill tip, which was abandoned along with the final 750 feet of pipe.

Despite that, the discovery is proving to be a lucky strike for Ormat Technologies, a Nevada-based company that operates the Puna Geothermal Venture on Hawaii's Big Island.

The hole is now in use as an "injection well" where water and condensed steam is returned to the ground to be reheated and then extracted through the "production wells" on the site. The plant now generates about 30 megawatts of electricity, and is in the process of expanding to 38 megawatts.