华北地区中等地震活动非稳态特征及预报效能研究

Study on Non-steady-state Characteristic of Moderate Earthquake Activity and Predict Efficiency in North China

采用全时空扫描方法在时空强三维轴上识别华北地区的中等地震活动的非稳态震兆信息。结果表明,在地震孕育过程中中等地震活动有由稳态向非稳态演化的特点。非稳态图像不同于传统意义上的空区和条带,其空间分布范围较大,一般出现在震前1年左右。以发生在非稳态图像的非开放、非卸载端点(交汇点)的地震作为标志地震,预测其周围(r=100 km)2年内发生MS≥5.0地震,预报能力评分R=0.573。

Adopting the method of whole time-pace scan on the 3D axial of time, space and strength, the non-steady-state precursory information of moderate seismic activity is identified. The result shows that the characteristic of moderate seismic activity changing from steady-state to non-steady-state is exist in the course of an earthquake pregnant. The non-steady-state seismicity pattern is different from traditional seismic gap and band, its spatial scope is bigger and it often appears about one year before the earthquake. It is called sign earthquake when the earthquake occurs not at open or unload end point （ intersection point） of non-steady-state pattern. Using the sign earthquake to predict the Ms ≥15.0 shock inner 100 km range in future 2 years, its prediction efficiency is R =0. 573.