Microearthquake Survey of the Radium Springs KGRA, South-Central New Mexico

Abstract

For a nine week period during September, October and November of 1975, seismicity was monitored in the area of Radium Springs Known Geothermal Resources Area (KGRA) located in South-central New Mexico in the Rio Grande Rift. The seismic array consisted of five, three component seismograph stations with maximum station separation less than 15 km. Two micro earthquakes with coda duration magnitudes of 0.0 were located and are apparently associated with surface mapped faults in the near proximity of the hot springs. By far the most abundant type of local seismic activity, hundreds of events per day, were nanoearthquakes of from 0.25 to 2.0 sec total duration corresponding to coda magnitudes of -3.2 to -1.1. These nanoearthquakes are caused by natural hydro fracturing associated with the local geothermal regime.