On the canalization of seismic energy

Tlie paper shows how the velocities of the channel wavesPa and 8a, as thus far calculated, are apparent velocities. From such apparentvalues it is easy to calculate the real velocities, which coincide with theminimum velocity of longitudinal and transversal waves, calculated by15. Gutenberg and by Miss I. Lehmann for the astenospliere.The canalization of seismic energy is a general phenomenon which, inthe case of strong earthquakes with focus ca. 100 km deep, may involve notonly the astenospliere, but also tlie earth crust channels. Important examplesare alleged.The paper finally shows that also tlie energy developped by deep earthquakes(600 km deep and more) undergoes remarkable canalization. However,this concerns to a significant extent only the astenospliere.