Geothermal Visual: Seismograph Record of Passing Trains Vs. EGS Stimulation
Leslie Blodgett November 29, 2013

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Courtesy of Trenton Cladouhos, Senior Vice President R&D, AltaRock Energy

This photo shows a seismograph record from an instrument in La Pine, Oregon, the nearest town to AltaRock Energy’s Newberry Enhanced Geothermal Systems (EGS) demonstration, on the day of the project’s largest microseismic event on December 7, 2012.

The seismograph shows that at this site the ground motion of six passing trains produced a much greater effect than the largest hydraulic stimulation event (Mw 2.4), which was not even detected by this instrument. EGS can cause “hundreds of small microseismic events” (National Research Council); these events are several thousands of times smaller than is noticeable....