I live in Ventura County and I have had a life long
interest in plate tectonics, volcano's ,seismology ,geology basically
the whole earth science thing. I recently discovered, using Google
Earth a correlation between recent localized earthquake swarm activity
and geothermal electrical power producing plants on the west coast .
I found through the USGS web sites, KML/ KMZ files that once are
loaded into Google Earth would allow me to view recent earthquakes. I
also found KMZ files that would identify volcanoes and also one that
would identify hot springs and thermal activity.

Viewing these I soon saw a correlation between where the earthquakes
are happening and where hot springs, magma chambers etc are located,
What wasn't clear was what was the process that was causing the swarm.
Using Google Earth I zoomed in on one of the clusters near Clear Lake
northeast of San Francisco and right there in the middle of it was a
geothermal power plant!

Doing more research on the USGS web site I found out there are a
number of plants there that help produce a great deal of the power
for the Bay area. I also found out that there was other geothermal
plants producing a great deal of power in of all places--- the Salton
Sea area! Every area of Calif. where there seems to be clusters of
minor earthquakes or swarms, is also an area where geothermal power
plants that are working trying to meet mans need for power. The same
can be seen in Nevada and Utah. There is also one in Hawaii. On the
big island that recently had two large earthquakes. There are nearly
70 geothermal power plants currently operating in California, Nevada,
Utah, and Hawaii.

But why the earthquake clusters? The process of creating geothermal
power is to pump out the super heated brine(steam) from near the
subterranean magma source which is basically used to turn turbines to
generate electricity. But what to do with this cooled brine after the
process? Cooled geothermal water from the plants is injected back
underground.

Magma is very flexible when in its natural state, of course we have
all seen photos of magma flows, but when you pump cool water back into
the same area trying to extract more heat the magma becomes cold,
turns to schist, is under great stress and "breaks" releasing energy .

I am not saying all earthquakes are the result of these activities,
but we are all aware of mans ability to mess up our environment in
pursuit of the almighty dollar. Do your own research. Here are some
links to sites that I used in mine.

http://www.geology.sdsu.edu/localgeology/getour.html

http://www1.eere.energy.gov/geothermal/powerplants.html

http://www.geothermalhawaii.com/

http://www.unr.edu/Geothermal/GoogleEarth.htm

http://earthquake.usgs.gov/regional/qfaults/google.php

http://rockyitr.cr.usgs.gov/rmgsc/apps/Main/geiDownloads.html

more information on this subject can be found here or Google "induced earthquakes"

• Source processes of industrially-induced earthquakes at The Geysers geothermal area, California