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在Wake岛附近1500km长的海底地震台阵上记录到千岛群岛的地震,分析其海洋P波与S波数据,得到西太平洋的高频地震衰减的约束。确定了群速度为8.2—3.0km/s和频率为2.5—22.5Hz间的空间衰减和Q值。在上述频率范围内,海洋P波比S衰减大,它表明岩石圈内存在明显的体积衰减,或者海洋P波以波能漏失的形式传播。海洋P波与S波的视衰减与距离有关,在30°以外,衰减较弱。海洋P波的视Q随频率Q～f~(0.7)而增加,在2.5Hz时约为300,而在17.5Hz时增加约为1500。海洋S波的视Q也随频率Q～f~(1.1)而增加,在2.5Hz时约为400,而在22.5Hz时变化约为3000。
Earthquakes on the Kuril Islands were recorded on a 1500 km-long submarine seismic array near Wake Island and their P and S wave data were analyzed to obtain the high-frequency seismic attenuation in the western Pacific. The space attenuation and Q value of the group velocity of 8.2-3.0km / s and the frequency of 2.5-22.5Hz were determined. In the above frequency range, ocean P wave ratio S attenuates, indicating that there is a clear volume decay within the lithosphere or that ocean P waves propagate as wave energy loss. The apparent attenuation and distance of P wave and S wave in the ocean are related to the attenuation. At 30 °, the attenuation is weaker. The Q of oceanic P waves increases with frequency Q ~ f ~ (0.7), about 300 at 2.5 Hz and about 1500 at 17.5 Hz. The apparent Q of ocean S waves also increases with frequency Q ~ f ~ (1.1), about 400 at 2.5 Hz and about 3000 at 22.5 Hz.