华东地区地震空区预报效能评估

Assessment on Forecasting Effectiveness of Seismic Gap in Eastern China

对华东地区1970年以来的地震空区进行了预报效能评估。结果表明:ML≥3.0地震空区的报准率为0.45,虚报率为0.55,漏报率为0.57,R值为0.26;ML≥3.5地震空区的报准率为0.31,虚报率为0.69,漏报率为0.75,R值为0.08;ML≥4.0地震空区无对应的MS5.5以上地震。ML≥3.0地震空区的R值高于具有97.5%置信水平的R0值,具有一定的预报能力,ML≥3.5和ML≥4.0地震空区不具有预报能力。主震一般发生在空区内部边缘,震前空区一般不会被打破;空区的持续时间、空区尺度、震级下限与主震震级无明显线性关系;空区主要分布在江苏、山东及附近海域。

In this paper, forecasting effectiveness of seismic gap was evaluated in Eastern China since 1970. The results show that accurate rate of ML≥3.0 earthquakes gap is 0.45, inflating rate is 0.55, missing rate is 0.57, R value is 0.26. The values of ML≥3.5 earthquakes are 0.31, 0.69, 0.75 and 0.08 respectively. ML≥4.0 gap without corresponding to MS≥5.5 earthquake. R value of ML≥3.0 earthquakes gap is higher than R0 value of 97.5% confidence level, and is has certain forecasting capability, ML≥3.5 and ML≥4.0 earthquakes gap have no forecasting capability. The mainshocks are usually located in the gap and near the edge, the gap will not be broken before an mainshock. There is no obvious linear relationship between the gap lasting time, gap scale, magnitude lower limit and mainshock magnitude. The gaps are mainly distributed in Jiangsu, Shandong and adjacent sea areas.