图9  和田7.1级地震前后M_S≥4.0地震活动分布图

(a) 1970~1980.9；(b) 1980.10~1996.2；

(c) 1998~2001.6；(d) 以35.0°N、78.9°E为中心R-t图

Fig.9  Epicenter distribution of M_S≥4.0 earthquakes before and after

       the M_S 7.1 Hetian earthquake