论文部分内容阅读
2003年9月25日(世界时)十胜近海地震(M_w～8.0)随后的GPS时间序列揭示出了显著形变。我们采用“网络反演滤波”技术,对震后30天内后续断层滑动的时空演变进行了反演。后续断层滑动集中在同震破裂带附近,即在2003年地震断裂带、1968年十胜近海地震和1973年根室近海地震震源区之间的位置。反演表明,2003年地震断裂带中断层滑动速率衰减迅速,而周围地区衰减速度较慢。后续断层滑动地区的应力一速度路径大致遵循dr/d 1n(v)～0.6 MPa,这暗示着稳态速度强化摩擦。尽管不能排除其他的解释,但在沿走向的方向上,同震破裂和后续断层滑动互补的空间模型还是可能表明了摩擦特征的空间变化。
September 25, 2003 (World Time) The subsequent GPS time series of the Tokachi Offshore Earthquake (M_w ~ 8.0) revealed significant deformation. We use the “network inversion filtering” technique to invert the spatio-temporal evolution of subsequent fault slip within 30 days after the earthquake. Subsequent fault slip concentrated in the vicinity of coseismic ruptures, that is, between the 2003 earthquake fault zone, the 1968 Tokachi Offshore Earthquake and the 1973 root-zone offshore earthquake focal zone. Inversion shows that the fault slip rate attenuated rapidly in the 2003 earthquake fault zone, while the surrounding area decayed slowly. The stress-velocity path of the subsequent fault-slip region generally follows dr / d 1n (v) ~ 0.6 MPa, implying steady-state speed-enhanced friction. Although other explanations can not be ruled out, the spatial model of co-seismic rupture and subsequent slip-slip complementary along the strike may still indicate the spatial variation of frictional features.