Is Geothermal Drilling Causing Earthquakes?

Posted by Hannah Wiggins

Geothermal power is emerging as a significant player in the alternative energy space, with operations cropping up around the world and high hopes for powering significant numbers of homes and businesses as an alternative to traditional electricity. But as with all prospects in alternative energy, geothermal power is not without its downside. Currently, a great deal of effort is being poured into determining just how damaging geothermal drilling is – or if it even exists. The question of whether geothermal drilling can trigger, either directly or indirectly, the harrowing natural disaster of earthquakes has been generating quite a bit of buzz lately. So how is the verdict on this controversial topic coming along?

One school of thought proposes that our activities in international geothermal drilling simply aren’t intense or widespread enough to have much of an impact on seismic activity. The argument here primarily rests within the idea that the Earth is pretty big, pretty powerful, and is able to get by pretty well without caring much about our relatively tame activities in drilling. A geologist with a specialty in volcanoes, Erik Klemetti posits that in terms of depth and breadth, geothermal drilling simply doesn’t have enough power to set off volcanic eruptions, phenomena which also relies on the movements of the planet’s fault lines as well as tectonic plates. Klemetti’s opinion is culled from the investigation of recent eruptions on an island in the Philippines, where twenty earthquakes took place in succession shortly following geothermal drilling on the Canlaon Volcano. Proponents of this idea of the inability of human efforts to greatly affect the Earth’s eruptions point out that while it can be tempting to link seismic activity with nearby or recent drilling projects, these seemingly coincidental events are not enough to imply causation.

On the other hand, some areas have experienced anomalies in seismic activity that are otherwise hard to explain. Two years ago in Basel, Switzerland, the town experienced a magnitude 3.4 earthquake followed up by a series of sixty aftershocks of varying intensity. While the area typically endured a small collection of similar quakes throughout the year, this event directly correlated with the activities of the town’s geothermal power plant, which had injected water into the Earth’s underlying dry rock and was awaiting the super-heated recovery. The power plant’s parent company had warned local legislators and residents that the risk of earthquakes due to their activity was a concern. Beyond this and similar instances that make a strong case for the possibility of geothermal drilling to cause quakes, some prominent academics such as Columbia University’s Christian D. Klose have attributed over 200 earthquakes to human activity –and the results of some have been disastrous.

After weighing both sides of the argument, it’s clear that we’ve yet to develop a firm line on whether our progress in geothermal drilling has been responsible for quakes, or if it’s bound to be behind the next big tremor. But as new studies and inquiries are made into refining and developing this potential source for the escape from inefficient energy dependency, it’s clear that the potential to wreak geological havoc does exist.