Geologic structures in the aftershock region of the 1964 Alaskan earthquake

Abstract

Seismic and echo sounder profiles in the aftershock region of the 1964 Alaskan earthquake define a pre-existing zone of discontinuous faults in the area of maximum aftershock strain release. Steep reverse faults and possibly other types of steep faults occur in the zone; surface rupture has probably not been continuous along its full length during any Recent earthquake. The fault zone may represent a narrow area of maximum flexure and uplift in the broader area deformed during the 1964 earthquake. An anticline at the continental margin with local large structural relief was also uplifted during the earthquake.