A Joint Seismic and Space‐Based Investigation of the 2016 Lamplugh Glacier and 2017 Wrangell Mountains (Alaska) Landslides
A Joint Seismic and Space‐Based Investigation of the 2016 Lamplugh Glacier and 2017 Wrangell Mountains (Alaska) Landslides
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DOI：
10.1029/2022jf006903
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发表时间：
2023-02
期刊：
影响因子：
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通讯作者：
Xinyu Luo;W. Fan;Y. Fialko
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文献类型：
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作者：
Xinyu Luo;W. Fan;Y. Fialko
山体滑坡通常发生在地形陡峭、降水丰富的地区，对当地社区造成重大危害。一些已知最大的山体滑坡发生在阿拉斯加，其中几次引发了当地海啸。由于缺乏观测，偏远地区的许多山体滑坡可能未被发现。在这里，我们开发了一个半自动化工作流程，使用地震和大地测量观测来检测、定位、验证和表征阿拉斯加的山体滑坡。地震观测在连续监测滑坡发生方面显示出了前景，而遥感技术非常适合滑坡的验证和高分辨率成像。我们利用 2016 年 6 月 28 日的兰普卢冰川山体滑坡验证了我们的程序。我们还提供了对 2017 年 9 月 22 日在兰格尔山脉地区发生的一次先前未知的山体滑坡的观察结果。兰格尔山滑坡产生了横跨阿拉斯加和美国本土记录的连贯表面波场。我们使用 Sentinel-1 合成孔径雷达和 Sentinel-2 光学图像来绘制各自的质量沉积图。为了研究滑坡动力学，我们反演了质心单力破坏模型的区域地震表面波数据。我们的模型表明，兰格尔山滑坡持续了大约 140 秒，并且发生了两次子事件，涉及至少五个不同的阶段。我们估计，山体滑坡已使 3.1-1340 万吨岩石移位，覆盖范围约 2 公里。我们的结果表明，结合地震和大地测量观测可以极大地改善阿拉斯加和其他地区偏远地区滑坡的检测和表征，为滑坡动力学提供新的见解。
Landslides commonly occur in areas with steep topography and abundant precipitation and pose a significant hazard to local communities. Some of the largest known landslides occur in Alaska, including several that caused local tsunamis. Many landslides may have gone undetected in remote areas due to lack of observations. Here, we develop a semiautomated workflow using both seismic and geodetic observations to detect, locate, validate, and characterize landslides in Alaska. Seismic observations have shown promise in continuously monitoring landslide occurrence, while remote sensing techniques are well suited for verification and high‐resolution imaging of landslides. We validate our procedure using the 28 June 2016, Lamplugh Glacier landslide. We also present observations of a previously unknown landslide occurred on 22 September 2017 in the Wrangell Mountains region. The Wrangell Mountains landslide generated a coherent surface wavefield recorded across Alaska and the contiguous United States. We used Sentinel‐1 Synthetic Aperture Radar and Sentinel‐2 optical imagery to map the respective mass deposit. To investigate the landslide dynamics, we inverted regional seismic surface wave data for a centroid single force failure model. Our model suggests that the Wrangell Mountains landslide lasted for about 140 s and had two subevents involving at least five distinct stages. We estimate that the landslide had displaced 3.1–13.4 million tons of rocks over a distance of ∼2 km. Our results suggest that combining seismic and geodetic observations can vastly improve the detection and characterization of landslides in remote areas in Alaska and elsewhere, providing new insights into the landslide dynamics.