本文应用1966—1976期间,甘肃南部和四川北部地区地震P波初动方向资料,求出平均节面解,据此推断松潘—平武7.2级地震前,孕震应力场的最大主压应力方向为近东西向。但由松潘台资料所得最大主压应力轴的方向,在震前显示出近90°的转动。 由余震资料所得释放应力场的最大主压应力方向,亦为近东西向。 In this paper, by using the data of the initial P wave direction in the areas of southern Gansu and northern Sichuan during 1966-1976, the mean nodal solution is obtained, and the maximum principal compressive stress direction of the pregnant earthquakes before the Songpan-Pingwu M7.2 earthquake is deduced For the near east-west. However, the direction of the maximum principal compressive stress axis obtained from Songpantai data shows a rotation of nearly 90 ° before the earthquake. The direction of the maximum principal compressive stress of the released stress field obtained from the aftershock data is also near east-west.