海底地震噪音的最新测量意外地揭示频率超过3赫兹的噪声水平很低(图1,略)。在某些情况下,3—15赫兹的噪声幅值等于或低于最好的大陆地震台的噪声幅值。如果像大多数大陆地震台所观测到的那样,即只有地方震震相才具有这种频率,那么上述结果就没有什么意义。然而,在深海低噪声环境中的实际观测表明,有两类远震震相在高频段具有相当高的信噪比。第一类由在洋底或沿大洋边缘发生的地震产生的 P_0/S_0。震相构成(即海洋 P 波/海洋 S波)。首先到达的 P_0/S_0。震相分别以每秒8.0和4.6公里相当稳定的视速度传播,而峰值传播速度分别约为每秒7.6和4.5公里,相当于地 Recent measurements of seabed seismic noise unexpectedly revealed that the noise levels at frequencies above 3 Hz were low (Figure 1, omitted). In some cases, the noise amplitude of 3-15 Hz is equal to or lower than the noise amplitude of the best continental seismograph. If, as most mainland seismostats have observed, only local seismic phases have this frequency, the above result is meaningless. However, the actual observations in the deep ocean and low noise environment show that there are two types of teleseismic phases with a rather high signal-to-noise ratio at high frequencies. The first type is P_0 / S_0 generated by earthquakes that occur on the ocean floor or along the edge of the ocean. Seismic phase composition (ie, marine P wave / ocean S wave). The first arrival of P_0 / S_0. Seismic phases propagate at fairly constant apparent velocities of 8.0 and 4.6 kilometers per second, respectively, while the peak velocities are approximately 7.6 and 4.5 kilometers per second, respectively, equivalent to