中国大陆14次强震前电离层异常统计分析

Statistical analysis of seismo-ionospheric perturbation before 14 Ms ≥ 7.0 strong earthquakes in Chinese subcontinent

摘要: 地震电离层扰动规律统计分析对开展地震监测、预测意义重大。利用四分位数法对中国大陆地区14次Ms≥ 7.0地震前电离层f_oF₂进行了统计,进一步证实了地震电离层异常的存在,并分析了地震电离层异常扰动的时间、空间分布规律以及扰动形态特点,给出电离层f_oF₂扰动与地震各要素之间的关系。统计结果表明:85.7%(12次)的地震在震前出现电离层异常,并且大部分分布在震前7天以内的11:00LT~17:00LT;此外,电离层f_oF₂扰动幅度与即将发生的地震震级、震源深度、震中距离存在不同程度的相关性。

Abstract: The statistical analysis of seismo-ionospheric perturbation is of significance to earthquake monitoring and prediction.We investigate the pre-earthquake ionosphere f_oF₂ associated with 14 Ms ≥ 7.0 earthquakes that occurred in Chinese subcontinent by quartile method,which confirms the existence of seismo-ionospheric perturbation.We analyze the distribution and morphology of these ionospheric disturbances to obtain the connection between the ionospheric disturbances and the earthquakes.Results show that the ionospheric anomalies appear prevailingly during 11:00LT~17:00LT within 7 days prior to 85.7% (12 earthquakes)of the 14 earthquakes.In addition,the ionospheric abnormal amplitude has some relationship with the magnitude,depth and distance of the forthcoming earthquake.