Crustal Deformation Related to the San Fernando Earthquake of February 9, 1971

Abstract

From the view point of earthquake prediction, the preseinmic movements related to the San Fernando Earthquake has been investigated, using the data of geodetic triangulation repeated in the area of the earthquake. A significant accumulation of tectonic strain before the earthquake has been detected from the analysis of retriangulation data. The axes of the maximum compression are in the direction of N-S, and the strain velocity is the order of 3-5⋅ 10^-7/year. This is harmonious to the faulting mechsaism of the earthquake. Records of some strain meters just before the earthquake have been also examined.