Seismicity of the Galápagos Islands and vicinity

Abstract

Abstract A study has been made of seismographically recorded submarine earthquakes between 1935 and 1961 in the region between 10°S and 20°N and 75°W and 110°W. Observational material on travel times was taken from the I.S.S., B.C.I.S. and U.S.C.G.S. catalogues for 191 earthquakes. New hypocentral solutions were found in each case by a uniform method of least-square adjustment. The earthquakes occur in the following belts: (a) the crest of the East Pacific Rise, (b) the Tehuantepec Ridge, (c) the Central American Trench, (d) the trench south of Panama and (e) around the Galápagos Islands. Focal depths and magnitudes of earthquakes are discussed. Escarpments appear to be aseismic.