论文部分内容阅读
2015年尼泊尔8.1级地震发生在喜马拉雅地震带上,为低角度逆冲型单侧破裂.余震区呈WNW-ESE展布,长轴约170 km,短轴约60 km.余震空间分布不均匀,主震和强余震分布在余震区两端,中部余震稀疏,这与8.1级地震矩释放主体区一致.7.5级地震发生在8.1级地震余震区的东部边缘,8.1级地震对其具有显著的触发作用.8.1级和7.5级地震发生在尼泊尔1505年和1934年两次大震之间的8级地震破裂空段上,1870年以来至本次地震前该破裂空段内没有发生过6级以上地震,存在6级地震背景空区.这次地震前13年,形成长约590 km的5级地震空区,震前19个月空区被打破.8.1级地震序列发生在5级地震空区的中部,其东、西两侧仍有较大范围没有发生地震,库伦应力计算表明8.1级地震对其东西两侧断层具有明显的触发作用.考虑到历史地震的离逝时间与复发周期,认为1934年地震破裂区再次发生大震的危险性较小,而1505年地震破裂区发生大震的危险性增大.2005年巴基斯坦M_w7.6和2015年尼泊尔8.1级地震的发生,表明喜马拉雅地震带已经进入了一个7级以上地震相对活跃的时段.
The magnitude 8.1 earthquake in Nepal occurred in the Himalayan seismic zone in 2015 with a low-angle thrust-type unilateral rupture.The aftershock zone was WNW-ESE with a major axis of about 170 km and a minor axis of about 60 km.After-earthquake spatial distribution was not uniform, The main shocks and strong aftershocks are distributed at both ends of the aftershock area, and the aftershocks in the middle are sparse, which is consistent with the release of the 8.1 magnitude earthquakes. The 7.5-magnitude earthquake occurred on the eastern edge of the 8.1-magnitude aftershock area. The magnitude 8.1 and 7.5 earthquakes occurred on the 8-magnitude earthquake rupture between Nepal and the two major earthquakes in 1934, and no earthquakes of more than magnitude 6 occurred before the earthquake between 1870 and the present After the earthquake, a magnitude-5 space of 590 km long was formed 13 years before the earthquake, and the 19-month airspace was destroyed before the earthquake. The 8.1-magnitude earthquake sequence occurred in a magnitude 5 earthquake area , There is still a large range of earthquakes on both the east and west sides. The Coulomb stress calculation shows that the magnitude 8.1 earthquake has obvious triggering on both east and west faults. Considering the elapsed time and recurrence period of the historical earthquake, it is considered that The danger of earthquakes occurred again in the rupture zone in 1934 Small, while the 1505 earthquake rupture zone of increased risk of earthquake. M_w7.6 Pakistan occurred in 2005 and 2015 Nepal earthquake of 8.1, indicating that the Himalayan seismic zone has entered more than a magnitude 7 earthquake relatively active period.