Abstract We simulate the strong ground motion for an expected major earthquake (Mw 7.0) beneath the Bhutan Himalayan region with an empirical Green's function method using waveforms recorded from the 2009 Bhutan mainshock (Mw 6.1) and its largest aftershock (Mw 5.1). Fault orientation and location of the simulated event extend the length of the fault plane determined from the 2009 Bhutan mainshock and aftershock along its strike. The simulated PGA values are compared with the results derived from a ground motion prediction equation (GMPE) for the Himalayan region and it is found that different levels of accelerations are associated with different rupture initiation points on the fault plane. It is observed that the NE Indian region is capable of generating peak ground acceleration (PGA) in exceedance to 121 cm/s2 for simulated earthquake (Mw 7.0). The maximum impacts of shaking will be on the sites located near the rupture initiation points that are poised to generate higher values of ground acceleration. To validate our simulation, we also estimate the extent of rupture directivity of the simulated earthquake with respect to four initiation points indicating that higher value of PGA and shaking duration exist either to South or to South-West azimuths from the imitated locations, which are corroborated with respective geology of the sites. This study suggests that areas of maximum ground shaking would occur in the vicinity of the source initiation where possibility of relatively stronger earthquake hazards does exist, which in turn requires attention for adoption of earthquake risk mitigation plans in view of impacts of trans-boundary earthquakes in the region.

中文翻译：

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印度东北部不丹喜马拉雅山下发生 7.0 级地震的强地面运动模拟及其跨界地震危害影响

摘要 我们使用 2009 年不丹主震 (Mw 6.1) 及其最大余震 (Mw 5.1) 记录的波形，通过经验格林函数方法模拟不丹喜马拉雅地区下方预期大地震 (Mw 7.0) 的强地面运动。模拟事件的断层方向和位置延长了由 2009 年不丹主震和沿其走向的余震确定的断层面的长度。将模拟的 PGA 值与从喜马拉雅地区的地震动预测方程 (GMPE) 得出的结果进行比较，发现不同水平的加速度与断层面上的不同破裂起始点有关。据观察，东北印度地区能够产生超过 121 cm/s2 的模拟地震峰值地面加速度 (PGA)（Mw 7. 0）。震动的最大影响将发生在靠近破裂起始点的地点，这些地点准备产生更高的地面加速度值。为了验证我们的模拟，我们还估计了模拟地震相对于四个起始点的破裂方向性程度，表明从模拟位置向南或西南方位角存在更高的 PGA 值和震动持续时间，这得到了证实与站点的相应地质。本研究表明，在震源附近可能发生较大地震灾害的区域会发生最大的地震动，考虑到跨界地震的影响，需要注意采取地震风险缓解计划。该区域。震动的最大影响将发生在靠近破裂起始点的地点，这些地点准备产生更高的地面加速度值。为了验证我们的模拟，我们还估计了模拟地震相对于四个起始点的破裂方向性程度，表明从模拟位置向南或西南方位角存在更高的 PGA 值和震动持续时间，这得到了证实与站点的相应地质。本研究表明，在震源附近可能发生较大地震灾害的区域会发生最大的地震动，考虑到跨界地震的影响，需要注意采取地震风险缓解计划。该区域。震动的最大影响将发生在靠近破裂起始点的地点，这些地点准备产生更高的地面加速度值。为了验证我们的模拟，我们还估计了模拟地震相对于四个起始点的破裂方向性程度，表明从模拟位置向南或西南方位角存在更高的 PGA 值和震动持续时间，这得到了证实与站点的相应地质。本研究表明，在震源附近可能发生较大地震灾害的区域会发生最大的地震动，考虑到跨界地震的影响，需要注意采取地震风险缓解计划。该区域。