Maurer J M, Schaefer J M, Russell J B, Rupper S, Wangdi N, Putnam A E, Young N
Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA.
Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA.
Sci Adv. 2020 Sep 16;6(38). doi: 10.1126/sciadv.aba3645. Print 2020 Sep.
Glacial lake outburst floods (GLOFs) are a substantial hazard for downstream communities in vulnerable regions, yet unpredictable triggers and remote source locations make GLOF dynamics difficult to measure and quantify. Here, we revisit a destructive GLOF that occurred in Bhutan in 1994 and apply cross-correlation-based seismic analyses to track the evolution of the GLOF remotely (~100 kilometers from the source region). We use the seismic observations along with eyewitness reports and a downstream gauge station to constrain a numerical flood model and then assess geomorphic change and current state of the unstable lakes via satellite imagery. Coherent seismic energy is evident from 1 to 5 hertz beginning approximately 5 hours before the flood impacted Punakha village, which originated at the source lake and advanced down the valley during the GLOF duration. Our analysis highlights potential benefits of using real-time seismic monitoring to improve early warning systems.
冰川湖突发洪水（GLOFs）对脆弱地区的下游社区构成重大危害，但触发因素不可预测且源头位置偏远，使得冰川湖突发洪水的动态难以测量和量化。在此，我们重新审视1994年在不丹发生的一次破坏性冰川湖突发洪水，并应用基于互相关的地震分析方法，对距离源头地区约100公里处的冰川湖突发洪水的演变进行远程追踪。我们利用地震观测数据，结合目击者报告和下游水位测量站的数据，来约束一个数值洪水模型，然后通过卫星图像评估不稳定湖泊的地貌变化和当前状态。在洪水冲击普那卡村前约5小时，从1赫兹到5赫兹可明显观察到相干地震能量，洪水起源于源头湖泊，并在冰川湖突发洪水期间沿山谷向下游推进。我们的分析突出了利用实时地震监测改进早期预警系统的潜在益处。
