台风“梅花”的地震信号特征分析及其对小尺度地球圈层耦合的启示

In this paper we investigate the seismic characteristics of the 2011 Typhoon "Muifa" on 3 broadband seismic stations. We find that the landing of ocean storms directly influences spectrum amplitudes of microseisms, showing an "increase-peak-decrease" pattern, whereas they exert no direct influence on Earth's hum and the high-frequency noise. Compared with our previous study on ocean storms in South China Sea, we found that that the coupling of ocean-continent is not only affected by local coastlines, bathymetry, paths of storms, landing directions, but also the water depth. As the ocean floor of East China Sea is flat, not as steep as that of South China Sea, and the water depth is shallow, the seismic motions for microseisms are excited more efficiently in vertical directions instead of horizontal directions shown in South China Sea. However, high-frequency noise is excited more efficiently in horizontal directions, the same as observed in South China Sea. This is because its source is local offshore wind, not influenced much by water depth and the bathymetry. High-frequency noise shows one-day periodicity, as its source is influenced greatly by the solar wind which has one-day periodicity. Lastly, we find that the energy may be passed more efficiently through ocean-continent than atmosphere-continent.