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设以某个时间为起点至 t 时刻前的给定时段里,受统一构造应力场控制的大范围内的累积应变释放量为ε_0=1/C(?),j 是全区地震总个数。在同一给定时段里,该范围内的第 K 个孕震区的累积应变释放量为(?),m_k 是第 K 区地震总个数。其中,假定受统一构造应力场控制的大范围内,C 为常数;Ei 和 El 为相应的地震波能量。定义(?)为第 K 区在 t 时刻前夕的相对应变量。一次大震发生后,应力要重新调整,这必将引起一个地区应力系统的改变。我们希望有一个量来表明:在统一构造应力场控制下,这种调整、变化的特点。研究川滇地区1500年以来,M≥5.0级的地震活动表明,这一过程可以用相对应变量 P_k(k=1,2,…,9)来近似表达。自1917年以来,9个孕震区的共10次大震都发生在 P_k≤0.08的区里,而不发生在>0.08的区;对每个孕震区,P_k>0.08的期间是安全期,反之为危险期。这可作为川滇地震危险区的一个参考判据。
Suppose the cumulative strain release within a wide range controlled by the unified tectonic stress field is ε0 = 1 / C (?) In a given period starting from a certain time until t, and j is the total number of earthquakes in the whole area . In the same given period, the cumulative release of strain in the K-th seismogenic zone in this range is (?), And m_k is the total number of earthquakes in Zone K. Among them, assuming a large area controlled by the unified tectonic stress field, C is a constant; Ei and El are the corresponding seismic energy. The definition (?) Is the corresponding variable of the k-th region on the eve of time t. After a major earthquake, the stress should be readjusted, which will inevitably lead to a change in the stress system in a region. We hope there is a certain amount of evidence to show that under the control of a unified tectonic stress field, the characteristics of such adjustment and change. Seismological activities of M ≥ 5.0 have been studied since 1500 years in the Sichuan-Yunnan region, indicating that this process can be approximated by the corresponding variables P_k (k = 1,2, ..., 9). Since 1917, a total of 10 major earthquakes in 9 seismogenic zones occurred in the area of P_k≤0.08, not in the area of> 0.08. For each seismogenic area, the period of P_k> 0.08 was a safe period , On the contrary is dangerous. This can be used as a reference for Sichuan-Yunnan earthquake danger zone.