Surface strain changes and strain energy release in the Dixie Valley-Fairview Peak Area, Nevada

Abstract

Observations by the United States Coast and Geodetic Survey before and after the 1954 earthquakes in the Dixie Valley-Fairview Peak area have been reduced to surface strain patterns. The strain analysis shows a predominant NW-SE extension in the epicentral areas of the Rainbow Mountain and Fairview Peak earthquakes and NW-SE contraction in adjacent areas. The pattern of strain changes thus conforms to an elastic rebound model. A minimum energy release of 1.3 × 1023 ergs was estimated from the elastic strain changes. This value is comparable to the total energy released by the four large 1954 shocks as approximated by means of the magnitude-energy conversion. Net lowering of the ground surface during the earthquakes indicates a release of gravitational potential energy of about 4.3 × 1023 ergs. This energy possibly was dissipated as a minor, undetected uplift in a broad region surrounding the epicentral area.