Hazards SEES Type 2: Magnitude 9 Earthquake Scenarios - Probabilistic Modeling, Warnings, Response and Resilience in the Pacific Northwest

卡斯卡迪亚9级地震（M9）将导致从不列颠哥伦比亚省到北方加州的震动、液化、山体滑坡和海啸。预计由此造成的损失将达数百亿美元，包括建筑物、桥梁和生命线受损，以及数千人伤亡。该项目解决了减少这种风险的科学和工程挑战。挑战首先是评估断层运动的分布范围，从而评估卡斯卡迪亚断层可能产生的震动和海啸。该项目解决了以前没有考虑的因素？断层上能量释放的分布和时间、断层运动频率含量随断层深度的相干变化以及沿着普吉湾的深盆地的3D效应-并将指定估计运动的不确定性，这对地震影响的概率估计至关重要，包括液化、滑坡、海啸和已建基础设施响应。该项目将开发新的概率，统计和数值方法，以提供更深入的洞察这些现象。这项研究将通过利用日本和智利的最新数据更好地解决潜在的物理问题，改善滑坡和液化的预测。该项目还将改进对海啸影响的估计，方法是制定更现实的海底变形设想方案，并估计夹带的碎片的冲击力。建筑环境对独特的长周期和长持续时间的地面运动的反应将使用先进的数值模拟进行概率评估。为了向美国地震预警的发展和部署提供信息，该项目包括对仅提供几秒钟或几分钟警告的信息的潜在影响进行访谈和调查研究。该项目将与当地社区和机构合作伙伴一道，通过比较利益攸关方如何解释（a）单一“最坏情况”灾害情景和（B）多种概率情景，以及如何将每种情景纳入社区应急准备和长期规划，提高概率信息的效用。该项目还将推动将概率评估纳入灾害教育。过去十年在M9级巨型俯冲地震的巨大风险方面提供了意想不到的教训。2004年的苏门答腊，2010年的智利和2011年的日本都造成了令科学家和居民惊讶的破坏。卡斯卡迪亚俯冲带的9级地震是太平洋西北部最大的自然灾害，为减少未来极端事件损失的跨学科研究提供了综合重点。为了应对降低风险的挑战，该项目汇集了来自学术界、政府和其他非营利组织的专家。共同愿景是通过在社会、建筑和自然环境中的预测、预警和适应性规划方面的综合进步，减少卡斯卡迪亚M9地震的灾难性风险。该项目将超越广义情景，转向对M9地震事件和随后的灾害进行概率预测，目的是将这些预测纳入社区抗灾规划，并提高地震预警系统的水平。

A Cascadia earthquake of magnitude 9 (M9) would cause shaking, liquefaction, landslides and tsunamis from British Columbia to northern California. The resulting losses, projected in the tens of billions of dollars, would include damaged buildings, bridges and lifelines, as well as thousands of human casualties. This project addresses scientific and engineering challenges in reducing this risk. The challenges start with assessing the range of distributions of fault motion and, therefore, the shaking and tsunamis that the Cascadia fault might generate. The project addresses factors not previously considered ? the distribution and timing of energy release on the fault, the coherent variation of frequency content of fault motion with fault depth, and the 3D effects of the deep basins along Puget Sound - and will specify the uncertainty in the estimated motions, which is critical to probabilistic estimation of earthquake impact, including liquefaction, landslides, tsunamis and built infrastructure response. The project will develop new probabilistic, statistical, and numerical methodologies to provide deeper insight into these phenomena. This research will improve forecasting of landslides and liquefaction through better resolution of the underlying physics with recent data from Japan and Chile. The project will also improve estimation of tsunami effects by developing more realistic scenarios of seafloor deformation and by estimating the battering power of entrained debris. Built-environment response to the unique long-period and long-duration ground motions will be evaluated probabilistically using advanced numerical simulation. To inform the development and deployment of earthquake early warning in the U.S., the project includes interview and survey research on the potential effects of messages that provide just a few seconds or minutes of warning. With local communities and agency partners, the project will improve the utility of probabilistic information by comparing how stakeholders interpret (a) single "worst case" hazard scenarios and (b) multiple probabilistic scenarios, and how each type of scenario is then incorporated into community emergency preparedness and long-range planning. The project will also advance the integration of probabilistic assessments into hazards education.The last decade has provided unexpected lessons in the enormous risks from giant subduction earthquakes of M9. Sumatra 2004, Chile 2010, and Japan 2011 each caused devastation that took scientists and residents by surprise. M9 earthquakes in the Cascadia subduction zone pose the greatest natural hazard in the Pacific Northwest and provide an integrative focus for interdisciplinary research on reducing future losses to extreme events. To address challenges in risk reduction, this project brings together experts from academia, government, and other nonprofit organizations. The shared vision is to reduce the catastrophic risk of a Cascadia M9 earthquake through integrated advances in forecasting, warning and adaptive planning across the social, built and natural environments. The project will move beyond generalized scenarios toward probabilistic predictions of M9 seismic events and the subsequent hazards, with the objective of integrating these into community resilience planning and advancing the state of earthquake early warning systems.