Recent results of earthquake study in Southern California

This report covers results which are partly already published, partly in course of publication, and partly still in preparation. The first synthetic study of earthquakes in southern California was published in 1932 [see 1 of "References" at end of paper]. In recent years available data have been much improved, owing to the installation of Benioff seismometers with high magnification at most of the stations, the establishment of new stations, and better chronometer-timing (six time-signals from the Naval Observatory are automatically recorded each day). Much experience in the interpretation of local seismograms has been gained with the continued occurrence of more and larger local shocks. The labor of calculation has been reduced by preparing special tables which quickly yield distances to 0.1 km [2].