(March 25, 2011) The April edition of the popular technology, engineering, and science news magazine, IEEE Spectrum, describes how “green” projects — geothermal energy, hydropower and carbon sequestration — may induce seismic activity.
Earthquakes Hinder Green Energy Plans
Hydropower Horror: Did a dam cause the Sichuan earthquake?
Quakes slow geothermal energy, hydropower, and carbon sequestration projects
By Peter Fairley / April 2011
The extraordinary earthquake in Japan last month and the terrifying tsunami that followed left the country’s electricity infrastructure crippled. But for some green technologies, the worry is not that they will be damaged by earthquakes but that they can cause earthquakes. Measured or anticipated seismic shocks associated with geothermal energy, hydropower, and carbon sequestration are raising questions about the wisdom of energy projects and in some cases stopping them in their tracks.
“We’re observing earthquakes. People are feeling them. The people running projects are denying responsibility, and I don’t think most people are buying it,” says seismologist David Oppenheimer, project chief for the U.S. Geological Survey’s Northern California Seismic Network. “It’s foolish to go in with eyes closed.”
Tectonic pressures cause the vast majority of earthquakes, but geophysicists also recognize the existence of human-induced seismicity. Hydropower reservoirs, for example, frequently cause small, shallow quakes as shifting water levels change the strains on the rock layers below. Such microseismicity—up to magnitude 4 on the Richter scale—is also caused by wells that inject hazardous waste and wastewater into deep rock formations at high pressure.
Microseismicity is merely an irritant, but human-induced seismicity can be deadly if it triggers the release of accumulated tectonic strain on a large fault. The textbook case occurred in 1967 when the filling of a reservoir behind India’s hydroelectric Koyna Dam—completed six years earlier—unleashed a magnitude 6.3 quake, killing 180 people and leaving thousands homeless. Geophysicists continue to debate whether the Zipingpu Dam, completed in 2004, triggered the 7.9-magnitude earthquake that devastated China’s Sichuan province three years ago, killing over 70 000.
Read the full story on IEEE Spectrum:
For more information on dam-induced earthquakes, visit Probe International’s Reservoir Induced Seismicity (RIS) section on this website.