Moment magnitude for small earthquakes in the Delaware basin of west Texas and southeast New Mexico, USA

Seismological Research Letters
By: , and 

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Abstract

The Delaware Basin region of west Texas and southeast New Mexico has become one of the most prolific regions of seismic activity in the continental United States due to widespread hydraulic fracturing and wastewater disposal injection. In response to the increased number of earthquakes in this region, rapid and accurate characterization of earthquake sources is necessary to understand the evolution of seismic activity and level of seismic hazard associated with these earthquakes. This study re-evaluates earthquake magnitudes, estimating moment magnitude (MW) for small earthquakes in the Delaware Basin using 1) moment-rate spectra derived from S-wave coda envelopes, and 2) a relative magnitude method that relies exclusively on the ratio of waveform amplitudes between highly correlated waveform pairs. The coda-envelope method produces accurate MW estimates for small earthquakes (M 1.5 – 3) that are consistent with independent, waveform modeled moment magnitudes for events with MW > 3. Using the relative amplitudes method to extend these MW magnitudes to many other events, we successfully provide relative moment magnitude (MW,rel) values for 81% of the Texas Seismological Network catalog in the Delaware Basin region, and 45% of the USGS Induced Seismicity Project’s catalog of events in southeast New Mexico. The adoption and integration of the calibrated MW,rel method with current magnitude estimation methods offers valuable insights into the relationships between local and moment magnitude and will contribute to improved characterization of widespread induced seismicity.

Suggested Citation

Gable, S., Huang, Y., Shelly, D.R., and Rubinstein, J.L., 2026, Moment magnitude for small earthquakes in the Delaware basin of west Texas and southeast New Mexico, USA: Seismological Research Letters, 13 p., https://doi.org/10.1785/0220250246.

ISSN: 1938-2057 (online)

Study Area

Publication type Article
Publication Subtype Journal Article
Title Moment magnitude for small earthquakes in the Delaware basin of west Texas and southeast New Mexico, USA
Series title Seismological Research Letters
DOI 10.1785/0220250246
Edition Online First
Publication Date May 27, 2026
Year Published 2026
Language English
Publisher Seismological Society of America
Contributing office(s) Earthquake Science Center
Description 13 p.
Country United States
State New Mexico, Texas
Other Geospatial southeast New Mexico, west Texas
Additional publication details