The determination of the extent of faulting with application to the Long Beach earthquake

Abstract

The Long Beach earthquake of March 10, 1933, produced no visible evidence to indicate the extent of faulting. The epicenter which Gutenberg and Wood located a few kilometers off the coast at Newport was determined by the arrival times of the first longitudinal waves. It therefore indicates solely the point at which faulting originated. It offers no information on the extent of faulting nor on the area from which maximum destructive energy radiated. The distribution of destruction was such as to suggest that faulting extended northwest along the Inglewood fault in the direction of Long Beach. Long Beach and Compton, distant 18 and 25 miles, respectively, from the epicenter, exhibited severe damage. With liberal allowances for poor construction and bad ground, it is difficult to believe that an earthquake of such small magnitude could produce damage of such severity at such large distances from the epicenter unless faulting extended a substantial distance toward Long Beach.