The Geysers: the world's largest geothermal field

Today’s Image of the Day from NASA Earth Observatory features the Geysers – the world’s largest geothermal field which is home a complex of 18 power plants. These plants use steam to drive turbines and generate electricity.

“About 1.3 million years ago, a large blob of silica-rich magma forced its way through Earth’s crust beneath the Coast Range of northern California. Today that shallow rock body is still piping hot, and the 45-square-mile area above it is known as The Geysers,” says NASA.

“Although the nearby Clear Lake volcanic field was still erupting as recently as a few thousand years ago, there were never any geysers at this geothermal field. The Geysers is a misnomer that came from 19th century settlers to the area who misunderstood the hot springs and fumaroles bubbling and steaming away in the canyon of Big Sulphur Creek.”

“From the mid-19th to the mid-20th century, a popular resort hotel operated in the area, while indigenous people of the region have visited the springs since prehistoric times.”

According to NASA, the turbines in this area can generate 725 megawatts of electricity, enough to power a city the size of San Francisco. In 2018, the turbines produced 50 percent of California’s geothermal power.

“Geothermal energy is produced by capturing heat from within the Earth, either via natural steam or very hot water. It is a reliable and renewable source of energy that can be available whether or not the Sun is shining or the wind is blowing,” explains NASA.

Image Credit: NASA Earth Observatory 

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By Chrissy Sexton, Earth.com Staff Writer