Surprising magma find captivates scientists
Magma discovery offers insight into continental rock formation process.
Tue, Apr 14, 2009 at 04:29 PM
Three developments in the geothermal world this month have caused more excitement in the field than these rock lovers tend to see in half a year. First up, drilling engineers accidentally tapped into a magma chamber in Hawaii while searching for new geothermal energy sites, geologists reported last week. The exceedingly rare discovery occurred in a geothermal field that was under development for power production.
The magma find provides an unexpected window into the process by which rock from the ocean floor forms into continental rock. Most of Hawaii is made of cooled lava, called basalt, which also makes up some of the ocean floor. The magma, however, is composed of elements that are more similar to the geology of continental rock, rather than basalt. Discerning the differences between the two types of rock could be key to unraveling the secrets of how continents form. A geoscientist quoted by National Geographic described it as his own Jurassic Park, on par with finding dinosaurs frolicking in the wild.
The only downside is that the significance of the magma site for scientific research may sideline efforts to build more geothermal power plants for Hawaii. But never fear, the geothermal energy field is practically thriving right now. Two new plants are about to begin producing power in Nevada, with production capacity of about 65 megawatts. That's enough energy to cover roughly 40,000 households and cuts carbon-dioxide emissions by about 300,000 tons of CO2 per year, says Enel North America, the company financing the plants. A typical coal plant produces about 500 MW of elecitricity, so the two new facilities aren't exactly the stuff of legend. However, many geothermal plants start small and then get expanded once they prove themselves by consistently producing power.
And in Africa, where geothermal energy production has long been viewed as a promising but far off technology, it may have just gotten a big boost. Preliminary studies, reported at the climate talks in Poznan, Poland, have found that the Rift Valley in East Africa could develop about 4,000 MW of electricity. Historically, geothermal energy has routinely been hindered by the high costs of drilling. With data as overwhelmingly positive as this, however, geothermal developers may finally start to sniff out a business plan for Africa.
Story by Sandra Upson. This article originally appeared in "Plenty" in December 2008.