Some Normal Earthquakes

Summary Normal earthquakes in Europe, Central Asia, and eastern and Western north America are discussed with reference to possible differences in the velocities of P and S at short distances. The average times of P between 2° and 10° would indicate the following values, velocities being over the surface. There are later and earlier readings referred to S , but the above values correspond to the most definite concentrations. Normal earthquakes capable of testing the S velocity in Japan were not found, but it is hoped that some with small and intermediate focal depths will give further information.