M 5.2 - Range Hill, Texas

Tectonic Summary

The December 16, 2022, M5.4 Texas earthquake occurred as the result of shallow normal faulting about 22 km north-northwest of the town of Midland, Texas. The earthquake occurred within the interior of the North America plate, far from any tectonic plate boundaries, and is therefore considered an intraplate earthquake. The preliminary focal mechanism solution for the earthquake indicates rupture occurred on a moderately dipping normal fault plane striking either to the northeast or southwest.

The region surrounding the December 16, 2022, earthquake is seismically active. Since 2018 about 120 earthquakes of magnitude 2.5 and larger have struck within 50 km of the recent quake. Larger earthquakes have struck in the broader area. A M5.4 earthquake struck on November 16th, 2022 about 200 km to the west and a M5.0 occurred on March 26, 2020 also about 200 km to the west of the December 16, 2022, earthquake. On Aug 1, 1975, a magnitude 4.8 earthquake occurred approximately 200 km to the west-southwest of this recent earthquake; however, a detailed history of small (less than magnitude 3) earthquakes in this region is not well know because the region was not well covered by seismometers until recent years.

Over the past two decades the central and eastern United States (CEUS) has experienced an increase in the occurrence of earthquakes. Scientific studies have linked much of this increase to human activity, predominantly wastewater injection into deep disposal wells. However, other mechanisms such as fluid withdrawal, enhanced oil recovery, or hydraulic fracturing processes can also result in induced earthquakes. In addition, regions with frequent induced events may also be subject to damaging earthquakes that would have occurred independently of human activity.

Making a strong scientific case for a causative link between a particular human activity and a particular sequence of earthquakes typically involves special studies devoted specifically to the question. Such investigations usually address the process by which the suspected triggering activity might have significantly altered stresses in the rocks at the earthquake source, and they commonly address the ways in which the characteristics of the suspected human triggered earthquakes differ from the characteristics of natural earthquakes in the region. Research suggests the March 2020, M5 Texas earthquake 200km to the west of the recent earthquake was the result a large increase in waste-water injection in the region.