It's not just deep well injection of fluids or coal mining that can trigger earthquakes. It is geothermal power production too.
Published in Science, a new study of geothermal generation 12 miles from a major California fault finds that the operation of the plant causes 1 earthquake every 11 days and that the number of earthquakes increases or decreases with the amount of power production. That's an ugly energy fact.
Geothermal power production has many strong environmental benefits. No air pollution. No water pollution. But this study is a reminder that all forms of energy production have environmental impacts.