Recent Earthquakes

Abstract

DR. G. VAN DIJK of the De Bilt (Holland) seismo-logical observatory recorded fifteen large earthquakes during August and fourteen during September 1939. One of the largest recorded at De Bilt was that of August 3, which probably had an epicentre 2,350 km. from De Bilt in an approximately easterly direction. Preliminary determinations of epicentres have been made by the United States Coast and Geodetic Survey in co-operation with Science Service and the Jesuit Seismological Association showing the earthquake of August 12 to have been in the north Pacific Ocean off Japan, that of August 24 in the Pacific Ocean near Central America, and that of August 26 in the Pacific Ocean near the New Hebrides. The somewhat deep focus (60 km.) earthquake of September 8 had an epicentre in lat. 51° N., long. 175° E., just south of the Andrean Islands, which are part of the Aleutian Islands. This was near the epicentre of the very strong ‘missing earthquake’ of November 10, 1938. The shock of September 21 had its epicentre near the island of San Luis in the Gulf of California in a region which is liable to small earthquake shocks. Kew reported that six strong earthquakes were registered on the seismographs during September, the latest to be recorded being on October 10, with a possible epicentral distance of 88° and rather deep focus (75 km.).