全国环境剪应力场动态变化与强震活动研究

通过采用陈培善等深入研究地震震源谱特征得到的地震短周期体波震级m_b和地震矩M_o与环境剪应力值的关系,测算地震剪切应力强度值f_o的方法,以及由中小地震近震震级M_L和面波震级M_S估算f_o的方法,对1993年至1998年1月发生在全国(包括台湾地区)m_b≥3.8,M_S ≤5.9 地震计算得到地震震源处的相对剪切应力强度f_o值,并确定出环境剪应力场高值分布区,对高剪应力值分布区与主要活动断裂、强震活动的相关关系进行了分析研究,对全国未来1~3年强震危险区及其危险性进行了预测。

RESEARCH ON RECENT DYNAMIC VARIATION IN ENVIRONMENTAL SHEAR-STRESS FIELD AND STRONG SEISMICITY IN CHINA

In this paper, using two methods to calculate seismic shear-stress strength f₀ obtained by Chen and others from the relation between short period body wave magnitude m_b, seismic moment M₀ and environmental shear-stress value in a thorough study of the characteristics of source spectrum and surface wave magnitudeM_S of moderate and small events, the authors calculated the relative shear-stress strength value f₀ in seismic source from the earthquakes with m_b ≥ 3.8 and M_S ≤ 5.9 occurred from 1993 to January, 1998 in China, determined the high-value distribution area of environmental shear-stress field, studied the correlation between the high-shear-stress distribution area and major active faults and strong seismicity, and forecasted strongly seismic risk areas and their risk in the coming 1~3 years in China.