地震电磁辐射定位和震级估算方法的探讨
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摘要
介绍地震电磁辐射短临预报方法国家地震局“八五”攻关项目的部分成果：①采用具有较强抗干扰能力的DPJ－Ⅲ型地震电磁辐射观测仪在几十kHZ的频率上进行单台来波方位扫描及定位研究，取得了二十几次观测震例，分析表明在几十kHZ频率上所观测到的震前电磁辐射异常信号的来源方位与震中方位是基本符合的；②收集国内218个震例资料，得到回归方程为MS=2.8＋2．1lgT，r=0．75，T为异常时间，利用这个关系式估算所预测地震的震级，在多数情况下误差为±0．5级。文章还介绍了使用上述方法时应注意的一些技术问题，例举了有关超低频段的观测震例。
This paper introduces part of the results of the seismo-electromagnetic emission in vest igations as a short-term and imminent earthquake prediction method in the key research project ofearthquake prediction during the "eighth Five-year Plan". ① Investigation has been made onscanning of the azimuth of the emission source and determination of the epicenter of the impending earthquake, based on a single station using the highly noise-resistant DPJ-Ⅲ type ofseismo-electromagnetic emission instrument with working frequency of tens kHz. Observational data of more than twenty earthquakes have been accumulated. Analysis of the anomaloussignals of seismo-electromagnetic emissions observed at frequency of tens kHz prior to theearthquakes shows that the azimuth of the emission sources usually agrees with that of the epicenters of the impending earthquake. ② Data of 218 earthquake cases in China have been col-lected and a regression formula has been obtained: Ms=2. 8 + 2. 1 lgT(r=0. 75)Where Tis the duration of anomaly in days. Errors in estimating the magnitude of the impending earthquakes by using this formula are usually less than 0. 5 magnitude unit. The paper also pointsout some technical details in application of the method on which attention should be paid. Anumber of observational examples at the ULF band have also been given.
This paper introduces part of the results of the seismo-electromagnetic emission in vest igations as a short-term and imminent earthquake prediction method in the key research project ofearthquake prediction during the "eighth Five-year Plan". ① Investigation has been made onscanning of the azimuth of the emission source and determination of the epicenter of the impending earthquake, based on a single station using the highly noise-resistant DPJ-Ⅲ type ofseismo-electromagnetic emission instrument with working frequency of tens kHz. Observational data of more than twenty earthquakes have been accumulated. Analysis of the anomaloussignals of seismo-electromagnetic emissions observed at frequency of tens kHz prior to theearthquakes shows that the azimuth of the emission sources usually agrees with that of the epicenters of the impending earthquake. ② Data of 218 earthquake cases in China have been col-lected and a regression formula has been obtained: Ms=2. 8 + 2. 1 lgT(r=0. 75)Where Tis the duration of anomaly in days. Errors in estimating the magnitude of the impending earthquakes by using this formula are usually less than 0. 5 magnitude unit. The paper also pointsout some technical details in application of the method on which attention should be paid. Anumber of observational examples at the ULF band have also been given.
引文
1 Hayakawa M,Fujinawa Y.Electromagnetic phenomena related to earthquake prediction.Terra Scientif-ic Publising Company,Japan,1994.631～639.
2 张德齐,王盛飞,刘福,等.江苏南黄海6.1级地震电磁辐射异常特征.地震学刊,1997,(2):23～26.
3 张德齐.地震电磁辐射前兆判据探讨.地震学刊,1992,(2):6～10.
2 张德齐,王盛飞,刘福,等.江苏南黄海6.1级地震电磁辐射异常特征.地震学刊,1997,(2):23～26.
3 张德齐.地震电磁辐射前兆判据探讨.地震学刊,1992,(2):6～10.
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