On the Big Island of Hawaii, something super hot and sticky welled up and made some scientists very happy.
It wasn't the black gold, but was priceless nevertheless. It was magma, the molten substance found deep in the earth and typically only comes up for a visit during a volcanic eruption.
Ormat Technologies found the superhot magma while drilling a geothermal well, and announced the discovery Tuesday at the American Geophysical Union meeting in San Francisco.
The discovery was the first time magma was found its natural environment instead of being ejected by volcano eruption, said Bruce Marsh, a geologist at the Johns Hopkins University and a magma expert, during a press event at the AGU meeting.
"It's like Jurassic Park – it's what's for me, to see this in its natural habitat," Marsh said. "This is a singular event, the first contact with inner Earth."
Being able to study magma underground will advance the understanding of what goes on beneath the Earth's crust. It also has greentech implications beyond geothermal energy development. Governments and private enterprises have been exploring ideas of drilling deep underground to store nuclear waste (Yucca Mountain project) or carbon emissions.
Ormat, based in Reno, Nev., began drilling the fateful well at is Puna Geothermal Venture field and power plant in eastern Big Island in 2005. After digging 2.5 kilometers (1.6 miles) deep, workers noticed something unexpected emerging from the well, said William Peplow, a consultant geologist for the drilling project, at the AGU meeting.
The temperature of the magma reached 1050 Centigrade, but it cooled into clear glass when it rose about 8 meters (26 feet), thanks to the cold drilling fluid being pumped into the well as part of the drilling process.
Peplow had expected to hit dark molten basalt because basalt is abundant on the island. Tests of the glass samples found that the material was dacite, an unusual type of magma that is granitic in nature and contains 67 percent of silica. Basalt is 50 percent silica.
Tests results that came back last week indicated that the magma might have been pushed closer to the Earth's surface during a 1924 volcanic eruption. It retreated but was moved closer to the surface again during a 1955 eruption, Marsh said.
Bruce said magma discovery already dispelled a theory that when you crushed the Earth's surface, the hot fluid underneath would "froth like a soda in a bottle." Instead, the magma was well behaved and stayed dense – Bruce said he didn't find bubbles in the glass samples.
The discovery will also benefit Ormat, which has been operating the Puna field and 30-megawatt power plant since 1993. The company has no commercial use for the magma, but the magma's high temperature means the rock surrounding it could be ideal for extracting geothermal energy.
At 1050 Centigrade, the place the magma dwelled is a whole lot hotter than the 500-Centigrade environment other geothermal energy developers look for. In Australia, geothermal energy developers are drilling down to 5 kilometers to look for rocks at 260 Centigrade.
Ormat plans to drill in areas above the magma chamber and inject water into wells to produce the steam necessary for electricity generation, said Lucien Bronicki, chairman and chief technology officer of Ormat, after the AGU press event.
Geothermal energy development is not new, but has garnered renewed interest from renewable energy advocates. Google invested $10.25 million in AltaRock Energy, Potter Drilling and a university lab for geothermal energy development earlier this year (see Google Funds Hot Rock Technology).