地磁加卸载响应比与地震对应关系研究

通过对浙、沪、苏邻近 4个地磁观测点的近十年的资料,及邻近区域10个地震进行了每日Z分量日变幅加卸载响应比随时间变化和响应比月均值的相关研究。结果表明:加卸载响应比阈值P₀(Z) 和响应比月均值P_M(Z)的大小与地震的震级、震中距及异常出现的早晚并非完全呈线性相关;当响应比值大于某一阈值时,有可能发生一定震级的地震 ;按该方法结果综合分析,截止1998年9月底,未来1年左右的时间内在该研究区域或更大范围(含台湾区域)有可能发生6级左右的地震。该方法可作为分析预报手段参与中短期和短临地震趋势判断的一种新方法。

Study on geomagnetic loading-unloading response ratio and earthquakes

We calculated and analyzed about ten years′ data on geomagnetic loading-unloading response ratio value P (Z) from magnetic stations in Zhejiang, Shang hai and Jiang su Provinces, and studied the relation of ten earthquakes which occurred in the three provinces and their vicinity and changes of the P (Z) and its monthly averag evalue P_M(Z). The results show that it is not acomplete linear correlation between the threshold value P₀ (Z) or P_M(Z) and the seismic m ag nitude or the epicentral distance or the o ccurrence time of anomalous P(Z) and P_M (Z). When P(Z) ≥ P₀(Z) at astation an earthquake maybe occur nearby.On the basis of synthetic analysis by this method, a strong earthquake with M_S ≥ 6.0 may occur in the research region or more largely area(including Taiwan area) within one year, by the end of September 1998. This method can be used as a new routine tool for judgement of the medium-short and short-term and imminent seismic tendency.