The Puerto Armuelles Earthquake (Southwestern Panama) of July 18, 1934

Abstract

The Puerto Armuelles Earhquake of July 18 1934 and its six main aftershocks nave been  relocated using a new version of Dewey's Joint Hypocenter Determination program: JHD89. The main event focal mechanism has been determinated from historical seismograms first arrivals. The results of this study  suggest that the active Panama, Balboa and possibly the Mykland fracture zones extent through the southwestern Panama continental shelf up to connect with faults inland as proposed by BERRAGE & THORPE (1988). The Burica Peninsula medial fault zone, stratigraphically infered by CORRIGAN (1986) also seems to be active. This group of parallel northwest trending right lateral strike-slip faults interact, at least for large events. The focal mechanism solution of the 1934 Puerto Armuelles Earthquake indicates a right lateral strike slip solution with a normal component.