UNDERSTANDING RECENT NORTH TEXAS SEISMICITY

A Scientific Investigation of the Reno-Azle and Mineral Wells Earthquake Sequences
by Seismologists from SMU’s Huffington Department of Earth Sciences in Dedman College

North Texas earthquakes occurring in the Reno-Azle area since Nov. 5, 2013, and in Mineral Wells since Nov. 28, 2013, have raised scientific questions about the nature of these sequences and heightened local and national concerns about the impact of shale gas production on infrastructure and subsurface structures.

While all North Texas events to date have been small (less than magnitude 4) seismologists are unable to evaluate the potential maximum magnitude for such faults and define the hazard.  Recognizing an immediate need to record the data necessary to understand these events, scientists at SMU have installed and are operating a temporary seismic network in the Reno-Azle area to acquire data that may be used to locate and characterize the current earthquake sequence.  

The primary research goal will be to conduct the data analysis needed to improve identification of earthquake location and characterize the size, mechanisms and accelerations associated with the events.  The improved network geometry and closer stations will make it possible to more accurately locate the events.  This will allow SMU scientists to estimate the size and nature of the fault(s), which may suggest the maximum size of the earthquake(s).  SMU also will be able to measure peak-ground-accelerations, which are needed to better estimate hazard.

Earthquake Study Team Graduate student Remi Oldham sets up equipment.

Finally, the spatial relation of the felt earthquakes to fluid injection points related to shale gas development in Texas and other states remains a major question.  Understanding if and/or how injection of fluids into the crystalline crust reactivates otherwise inactive faults has important implications for seismology, the energy industry, and society.  The number and diversity of instruments SMU has deployed is unique and provides an unprecedented opportunity to make progress on this topic. 

Instrumentation has been provided in part by the U.S. Geological Survey and the Incorporated Research Institutions for Seismology (IRIS).  All waveform data collected by SMU is publically available, archived at the IRIS Data Management Center.  Financial support for the study has been provided by SMU through the Huffington Department of Earth Sciences in Dedman College, the Institute for the Study of Earth and Man, and the University Research Council.

Location Of Seismicity Monitors

Blue circles indicate general locations of seismic stations. Yellow circles indicate National Earthquake Information Center seismicity through January 16, 2014.