A: It could, but it shouldn't. Government regulations require people who want to use CCS to carefully study whether or not the CO2 could possibly produce earthquakes deep underground. The government requires that the pressures and rates of injection are well below critical limits.
The energy in an earthquake comes from the force of one continent dragging against another or when continents collide causing one continent to subside beneath the other continent. Earth only accomplishes earthquakes by building up energy over a long time. If a fault is nearly ready to slip (this is called critically stressed), by adding a little lubrication and an energy bump, you can induce movement over a small area through underground fluid injection. However, the size of the earthquake is proportional to the size of the area that slips.
In the Superman movie, Lex Luthor was smart about the way he tried to start an earthquake. He went to work on an existing crack, or fault, where there’s already a weaknesses in the Earth’s crust. But it takes unimaginably huge amounts of energy to move rocks, even at a fault.
Really big earthquakes result from slip of 10’s of meters over a fault length of 100’s of kilometers, like the magnitude 8.9 earthquake that devastated Japan in March 2011. This can only happen at tectonic plate boundaries, and the forces involved are huge, hundreds or thousands of times larger than what can be attained by human-induced operations. The injection of CO2 is a much smaller scale activity.
Earthquakes have been induced by injection in the past, but only rarely.
In the 1960’s, the Army drilled a 12,000 foot deep disposal well at its Rocky Mountain Arsenal and began injecting fluid. Two induced earthquakes were felt in Denver. The region was particularly highly stressed naturally, and the injection of fluids is thought to have induced a series of earthquakes, with the largest being a magnitude 5.
In Basel, Switzerland, three earthquakes of magnitude 2.6, 2.7, and 3.4 were felt after water was injected into a well as part of a project to develop geothermal energy. Operations were immediately stopped. On the Richter scale, earthquakes between 3 and 4 are minor and do not cause damage.
Today, we don’t have Superman to protect us from earthquakes but we do have the Safe Water Drinking Act of 1974 and the Underground Injection Control program. Both of these regulations require prospective injectors to analyze the potential for induced seismicity. An injector must determine the current stress at the injection site, and calculate the energy that will be added during injection. Injection must then be performed at pressures and rates below a critical limit.
With proper testing and monitoring, induced seismicity is about as likely to happen as Lex Luthor defeating Superman.
Dr. Jon Olson of the Dept. of Petroleum and Geosystems Engineering, The University of Texas at Austin approved this FAQ.
A blog post by Bruce Hill of the Clean Air Task Force does an excellent job of summarizing the newest research on seismicity and carbon sequestration.
The US Department of Energy's Lawrence Berkeley National Laboratory has put together a somewhat technical primer on induced seismicity. To read more about the causess, controls, and impacts of induced seismicity, click the icon at the left.
For more on the Richter scale from the US Geological Survey, please click on the link to the right.