California rattled by rapid succession of earthquakes

"At least seven tremors have been reported, ranging in magnitude from 1.1 to 4.1, with the epicenter near The Geysers. The larger 4.1 magnitude earthquake hit first, detected at 7.08am PT (10.08am ET), and the rest were likely aftershocks, according to the US Geological Survey (USGS). Residents as far south as San Francisco reported shaking in the region, following the larger quake."

"The Geysers in the state is a large geothermal field in the Mayacamas Mountains, spanning Sonoma, Lake and Mendocino counties, which harnesses underground steam to generate electricity. Although it is called The Geysers, the area does not have actual geysers but rather steam vents called fumaroles, a name given by early settlers who misunderstood the natural phenomenon. The Geysers geothermal field in northern California lies atop a network of faults, including the Bartlett Springs Fault Zone and the Healdsburg-Maacama Fault system."

"The Geysers Geothermal Field, sprawling across roughly 45 square miles, sits about 72 miles north of San Francisco. Home to 18 geothermal power plants, the region is no stranger to tremors, as frequent minor earthquakes rattle the area as a direct result of the operations used to harness steam for electricity, according to the USGS. Workers and nearby residents can often feel the quakes beneath their feet."

A series of at least seven earthquakes struck near The Geysers in northern California, with magnitudes ranging from 1.1 to 4.1 and the largest detected at 4.1 at 7:08 a.m. PT. The USGS identified the smaller events as likely aftershocks and residents as far south as San Francisco reported feeling shaking. The Geysers geothermal field spans about 45 square miles across Sonoma, Lake and Mendocino counties and contains 18 geothermal power plants. The field sits atop multiple fault systems, including the Bartlett Springs and Healdsburg-Maacama faults. Steam extraction and reservoir pressure changes can contract rock and trigger tremors, and geothermal operations have been linked to frequent minor earthquakes in the area.

Read at Mail Online