Collaborative Research: Tying deep-seated landslides to base level, earthquakes, and a changing climate in the Pacific Northwest

在华盛顿州人口稠密的普吉湾地区发现了数千个史前滑坡沉积物，2014年SR 530“Oso”滑坡造成43人死亡。该地区还经历了其他危险，如地震和冬季暴雨，这可能引发了许多史前山体滑坡。该项目将全面绘制和估计过去滑坡的年代，以确定哪些滑坡可能是由独立已知的地震和气候事件引发的，从而改进对未来事件的危险估计。计划与负责绘制太平洋西北部滑坡灾害地图的州机构协调，以确保广泛传播项目成果。一个重要的重点是将可能由西雅图断层上的史前地震引发的山体滑坡与该地震引起的地面震动的基于物理学的计算机模拟联系起来。该项目将测试长期存在的概念模型，以响应三种主要的强迫机制：地震，气候和基准面。主要的技术目标是量化空间和时间上的滑坡模式，并根据独立的强迫机制记录评估该模式。为了确定实现这一目标所需的数千次滑坡的日期，研究人员将定义一个滑坡年龄的经验模型，该模型可以通过机载激光雷达数据进行有效的远程测量，并受到基准滑坡已知年龄的限制。模拟的地面运动从一套模拟西雅图断层地震的情况下，将被比较，滑坡可能引发的最近的史前破裂，以告知未来的危险估计和约束破裂参数。基于遥感的滑坡测年和三维地震模拟的新颖组合将促进对景观如何演变和产生危害的科学理解。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Thousands of prehistoric landslide deposits are found throughout the heavily populated Puget Sound region in Washington State, where the SR530 “Oso” Landslide killed 43 people in 2014. The region also experiences other hazards, such as earthquakes and heavy winter rain storms, that likely triggered many of those prehistoric landslides. This project will comprehensively map and estimate the ages of past landslides to determine which ones were likely triggered by independently known earthquakes and climatic events, thereby improving hazard estimates for future events. Coordination with state agencies responsible for creating landslide hazard maps in the Pacific Northwest is planned to ensure broad dissemination of project results. An important focus will be connecting landslides that may have been triggered by a prehistoric earthquake on the Seattle Fault to physics-based computer simulations of ground shaking caused by that earthquake.The project will test long-standing conceptual models for when and where landslides occur within the landscape in response to three main forcing mechanisms: earthquakes, climate, and base level. The main technical goal is to quantify the pattern of landslides in space and time and evaluate that pattern against independent records of forcing mechanisms. To date the thousands of landslides required to accomplish this goal, the researchers will define an empirical model for landslide age that can be efficiently measured remotely with airborne lidar data and constrained by known ages of benchmark landslides. Simulated ground motions from a suite of modeled Seattle Fault earthquake scenarios will be compared to landslides likely triggered by its most recent prehistoric rupture to inform future hazard estimates and constrain rupture parameters. The novel combination of remote sensing-based landslide dating and 3D earthquake simulations will advance scientific understanding of how landscapes evolve and generate hazards.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.