We infer that both the sharp deformation in the deep crust and the large-scale NW-trending Puchang and Selibuya fault structures may play a crucial role in forming the local stress perturbation.

• 震源区深部结构的陡变以及位于震源区东部边界规模较大的NW走向的普昌断裂和色力布亚隐伏断裂可能对产生这种横向非均匀的局部应力场起了重要的作用。