图21　通海7．7级地震前各种异常时空分布图

Fig．21  Time-space distribution 0f various anomalies

         before the Ｍ 7．7 Tonghai earthquake

         ①地震条带;　②地震空区;　③涝、旱振荡;

         ④破坏空区的早期前震;⑤气温场异常;⑥宏观异常