为连续地给出京津唐地区的应力场变化趋势,继1988年4月第2期《地震》上发表的京津唐地区1986年4月至12月间的小震震源机制的计算结果后,这次再给出这一地区1987年4月至1988年1月间,1.3≤M_L≤2.8的39个小震震源机制(表1),并给出机制解图(图1)与主压应力轴方向图(图2)。图1中的黑色区域为张应力区,白色区域为压应力区。 In order to continuously give the stress field trend in Beijing, Tianjin and Tangshan area, following the calculation results of the focal mechanism of small earthquakes in Beijing-Tianjin-Tangshan area from April to December 1986 published in the second earthquake in April 1988 , This time gives the focal mechanism of 39 small earthquakes with 1.3≤M_L≤2.8 (Table 1) in this area from April 1987 to January 1988 and gives the mechanism solution (Figure 1) and main pressure Stress axis pattern (Figure 2). The black area in Figure 1 is the tensile stress area and the white area is the compressive stress area.