A comparison of multiple solutions of focal mechanisms

Abstract

The occurrence of focal mechanism solutions of the same earthquake by different authors is examined. Of 42 instances of such multiple solutions for earthquakes which occurred around the borders of the Pacific Ocean, it is found that of 84 possible pairs of multiple solutions agreement is excellent in 8 cases, good in 13, fair in 19, poor in 19, and no agreement in 25. The implication for focal mechanism studies is illustrated by examining the focal mechanism solutions of deep-focus earthquakes under the Sea of Japan.