Fracking, short for hydraulic fracturing, is a method of extracting natural gas and oil from shale rocks deep underground. It involves injecting a high-pressure mixture of water, sand, and chemicals into the rock formations to release the trapped resources.
While fracking has been praised for its economic benefits and decrease in dependency on foreign oil, it has also been heavily criticized for its potential environmental and health hazards. One of the main concerns surrounding fracking is its potential to cause earthquakes.
What is an Earthquake?
Earthquakes are a natural phenomenon that occur when tectonic plates, massive slabs of rock that make up the Earth's crust, shift and release built-up energy. This sudden movement can cause vibrations on the surface, resulting in shaking and sometimes damage to buildings and structures.
What is an Induced Earthquake?
An induced earthquake is an earthquake that was caused by human activity. These activities include mining operations, geothermal energy production, intensive construction, and the injection of fluids into deep wells for waste disposal.
Wastewater Disposal and Seismic Activity
When it comes to fracking, the process itself does not directly induce earthquakes. However, the disposal of wastewater from oil and gas operations has been linked to increased seismic activity in certain areas. According to the United States Department of Energy, the primary source for induced seismicity near unconventional oil and gas operations is not from hydraulic fracturing (fracking), but rather the deep disposal of water associated from oil and gas production.
During the fracking process, large volumes of water are used to create fractures in the shale rock and release the trapped resources. This water, along with the added chemicals and natural substances from deep underground, becomes contaminated and needs to be disposed of. One common method of disposing of this wastewater is through injection wells, where the water is injected deep into the ground for storage or disposal. However, studies have shown that this process can potentially trigger seismic activity by increasing pressure on existing faults or creating new ones.
For an induced earthquake to occur, three main geological features must be present: 1) an existing fault, 2) subsurface stress conditions that bring the fault close to failure, and 3) a change in subsurface stress conditions caused by fluid injections or production activities. Even if these three features are present, it does not guarantee that an induced earthquake will occur. Other factors impact if fluid injection can induce an earthquake, including the distance between the injection well and the fault, and the volume of the injection.
Mitigating Induced Earthquake Risk
While there is evidence to suggest that wastewater disposal from fracking can cause earthquakes, it is important to note that not all injection wells have been linked to seismic activity. In fact, the majority of these wells do not cause any issues. To mitigate the risks, regulations and standards have been put in place to monitor and manage wastewater disposal. This includes monitoring the injection rates and pressures, as well as avoiding areas with known faults.
Earthquakes can have significant impacts on property and real estate, resulting in building damage or destruction. Property owners should be aware of the earthquake risk in their area to better prepare for the possibility of an earthquake. Similarly, as a part of the due diligence process, real estate developers must be aware of the potential for earthquakes in their area.
COMING SOON: Induced and natural earthquake risk reports for any U.S. property will soon be available in LandApp.