The Pawnee earthquake was the result of a significant increase in earthquakes throughout the Central United States beginning in 2009 due to the increased use of wastewater disposal in underground pipes by gas and oil operators. These and other incidents in the area caused public concern and prompted authorities to shut down the injection pumps and make new regulations on the injection of wastewater.
While earthquakes that humans cause have been recorded for over 100 years, the increasing numbers reported around the world have garnered a lot of scientific, political, and social interest. The causes of these earthquakes include industrial processes like mining or construction of water dams, as well as the injection of liquids, like wastewater and carbon dioxide, as well as extractions related to the exploration of gas and oil.
With the growing demand for energy and mineral resources around the world, the number of earthquakes that humans cause is expected to increase over the next years. Many of the most powerful and most destructive earthquakes of these past years have been caused by human-caused activities, such as the magnitude 7.9 Wenchuan (China) earthquake and the magnitude 7.8 Nepal earthquake.
Most of the time, industrial activities do not cause earthquakes. However, this can be a problem when these activities are located near active faults. In this instance, tiny stresses in the underground created by artificial processes can destabilize faults, leading to earthquakes.
Injections of fluids that are not correct
These stresses, like fluid injections, are capable of transferring across vast distances within the planet’s crust. This can cause earthquakes for days, months, and even decades after an injection.
Site for drilling in Basel, Switzerland. Keystone/Georgios Kefalas/Giorgos Michas, Author provided
The figure above illustrates that when the pressure of the fluid in the upper part of the well Basel 1 (purple line) increased during the injection and the induced seismicity rate as well (bluish bands). In the figure below, an average of the squared distance between the seismically induced earthquakes that occurred from the well is displayed. This shows the complicated spread of seismicity away from the well over time. The strongest earthquakes (magnitude over three depicted by stars) took place immediately after the injection was completed.
These issues, as well as the general ignorance of the exact strain and faulting conditions beneath the surface, make these earthquakes hard to predict or control.
In Europe, where populations are greater than in the United States, public concern regarding artificial earthquakes is greater. In the famous case of Basel, Switzerland, which occurred in 2006, around 11500 cubic meters of liquid were dumped under the pressure of a 5 km deep well in order to make extraction of energy from geothermal sources possible. In the course of the injection, there were more than 10,000 earthquakes occurred, and some of them were even powerful and were felt in Basel itself. This caused concern among the public and anger, which eventually led to the end of the project and the payment of more than 9 million in damages claims.
Nature’s work
In the situation in Southern Europe, which has a greater likelihood of natural earthquakes and landslides, the public’s tolerance for the induced earthquakes caused by industrial activities is more restricted. The devastating 2012. Emilia’s (Italy) series of earthquakes was the subject of continuous public debate and political debate because of the proximity of the epicenters of earthquakes in relation to an oilfield.
The Italian government set up an international commission to study whether there was a connection between seismicity in the region and the extraction of oil; however, there was no reason to exclude one. Another study found that these earthquakes could be natural. Natural phenomenon.
Another case of recent concern is the Castor project, which is an underground offshore gas storage facility located in the Gulf of Valencia, Spain. The $2 billion project was canceled by the Spanish government in 2014. Spanish administration in the year 2014 due to an explosion of seismicity in the region immediately following the start of gas injection operations and the subsequent public outrage that was triggered.