The earthquake of July 6, 1934: Amplitudes and First Motion.*

Abstract

Summary: The distribution of the first motion of the P waves for the earthquake of July 6, 1934, combined with knowledge of the general faulting trends of the region, leads to the conclusion that the earthquake was caused by movement on a Fig. 6.Berkeley Wood-Anderson seismograms of the earthquake of July 6, 1934. fault bearing about N 40° W, and dipping about 84° northeasterly. The displacement vectors dipped about 26° northwesterly. The displacement consisted of a motion of the Pacific side northerly and of the continental side southerly, as in 1906. This suggests an extension of the fault which broke in 1906 in Humboldt County. A second interpolation would give a fault bearing N 46° W.