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探索地震前兆是一件具有挑战性的研究。本文采用高通滤波的方法,处理分析了来自世界不同位置4个超导重力台站5次大地震前的秒级固体潮重力数据,发现在这些地震发生之前数天内,能够接收到稳定的重力高频扰动信号,其中2008年5月12日的汶川地震前出现一个主频为0.1-0.3Hz的重力扰动,而其他4次地震前出现两个主频为0.12-0.17Hz和0.06-0.085Hz的重力扰动。另一个发现是当地震发生在大陆与海洋板块断裂带时这种重力扰动信号具有远场效应,即重力扰动异常出现在距离震中较远的超导重力仪上,而较近的台站异常较小或没有异常。以上研究结果表明,这种重力扰动信号与地震发生具有较密切的相关性,可作为一种有潜力的临震预报信号;重力扰动信号的远场效应也许能够揭示某些地震发生前地球内部板块之间的相互作用机制。但由于地球上重力固体潮台站分布的非常不均匀,上述结果还需要今后研究更多的样本数据加以证实。
Exploring the earthquake precursors is a challenging research. In this paper, the high-pass filtering method is used to analyze and analyze the second-level solid tidal gravity data before the five earthquakes from four superconducting gravity stations at different locations in the world. It is found that a stable high gravity can be received within several days before these earthquakes occur Frequency disturbing signals. Among them, a gravity disturbance with frequency of 0.1-0.3Hz appeared before the Wenchuan earthquake on May 12, 2008, and two other dominant frequencies of 0.12-0.17Hz and 0.06-0.085Hz before the other four earthquakes occurred Gravity disturbance. Another finding is that the gravity disturbance signal has a far-field effect when the earthquake occurs in the continental and oceanic plate faults. That is, the gravity disturbance appears on the superconducting gravimeter farther away from the epicenter, while the closer station anomalies Little or no exception. The above results show that the signal of gravity disturbance is closely related to the occurrence of earthquakes and can be used as a potential signal for the prediction of earthquakes. The far-field effect of the signal of gravity disturbance may reveal some earthquakes before the earthquakes The mechanism of interaction between. However, due to the very uneven distribution of gravity tidal stations on the earth, the above results still need to be confirmed in future studies on more sample data.