Velocity and Response of Higher Mode Rayleigh Waves for the Pacific Ocean.

概要

論文の詳細を見る
Phase and group velocities and medium-response of higher mode Rayleigh waves are calculated for PC-MIN and PC-MAX, which are the upper mantle models proposed for the lowest- and the highest-velocity-areas in the Pacific (YOSHIBA, 1978). The former corresponds to the region of the ocean-floor age of 0 m.y. and the latter to that of 150 m.y. or more. Both phase and group velocity characteristics show that 1) the velocity difference of the higher modes, calculated for the two models, does not decrease with the period, 2) and this difference is largest for the second higher mode near 200 sec in group velocity and near 150 sec in phase velocity. For a shallow earthquake the medium-response of the higher modes is remarkably small compared with the fundamental mode. For a shock with a focal depth 200km, however, the response of the first higher mode near 40 sec is the greatest among the first four modes. This first higher mode at that period will be useful for the study of the low velocity layer under the ocean.
1979-03-31