Seismicity of fhe Los Alamos Region Based on Seismological Data

摘要

Estimates of seismic risk in the Los Alamos area based on only seismological evidence are presented. The data used in the study and tabulated in this paper were restricted to shocks occurring within 111 km of Los Alamos and includedn(1) noninstrumental reports of earthquakes prior to 1962 andn(2) instrumental studies of shocks from 1962 to 1972.nThe strongest earthquake to occur within the region of study during the 100-yr period, 1872-1972, had a probable magnitude of 5.5. Estimates of the strongest shock to occur in a 100-yr period based on extrapolation of the earthquake frequency-magnitude relation range from 3.9 to 5.4 depending on the data set used.nThe report recommends that seismic risk in the Los Alamos area be based on the recurrence of a magnitude 5.5 earth quake once every 100 yr somewhere within the Rio Grande de¬pression from Albuquerque to Questa. The seismicity of this part of the rift zone is (1) less than the Albuquerque-to-Socorro segment of the same structure and (2) substantially less than equivalent areas in Southern California.