1981年,1—5月,海丰梅陇地区连续发生一些小地震,截至5月底止,总计达1764次,其中M_L≥1.0的为477次,M_L≥2.0的为15次,最大震级为M_s=3.9。 据三分向梅陇地震台及三个单分向流动地震台测定,震中分布在海丰梅陇东南3.5—6公里的联安公社坡平一带。震中密集区长轴平行于海丰-梅陇断裂,沿北东向展布,长约5公里,短轴呈北西向,宽约3公里(图1)。震源深度为3—7.5公里,而90％的震源集中在深4.5—6.5公里处(图2)。震源体小,深度浅,不易积累大的应变能,这是小震群的一个明显特征。东京大学地震研究所过浦贤认为震群是发生在地应力 In 1981 and January-May, some small earthquakes occurred continuously in Meilong area of ​​Haifeng. As of the end of May, a total of 1764 times were found, of which 477 were for M_L≥1.0, and 15 times for M_L≥2.0. The maximum magnitude was M_s = 3.9. According to three points to Meilong Seismic Station and three single-point mobile seismograph measured, the epicenter distribution in Haifeng Meilong southeast of 3.5-6 km Lianan commune slope flat area. The major axis of the epicenter-dense area is parallel to the Haifeng-Meilong fault and is distributed along the NE direction. It is about 5 km long and has a north-west axis with a width of 3 km (Figure 1). The focal depth is 3-7.5 km, while 90% of the focal depths are concentrated 4.5-6.5 km deep (Figure 2). Small source body, shallow depth, not easy to accumulate large strain energy, which is a clear feature of small swarm. Earthquake Research Institute, Tokyo University Po Puxian that the earthquake swarm is occurring in the earth stress