RAPID: Recording Tsunami Impacts from the Taan Fjord, Alaska Landslide of October 17th, 2015

RAPID：记录 2015 年 10 月 17 日阿拉斯加塔安峡湾山体滑坡的海啸影响

• 批准号: 1650357
• 负责人: Patrick Lynett
• 金额: $ 3.99万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1650357&HistoricalAwards=false
• 关键词: RAPID; Recording; Tsunami; Impacts; Taan

On October 17th, 2015, the largest landslide in North America in decades occurred in Taan Fjord, an arm of southeast Alaska's Icy Bay. The landslide triggered an enormous local tsunami. Flow indicators from satellite imagery suggest that the maximum tsunami runup immediately adjacent to the slide mass exceeds 190 m. Such a maximum runup would be second only to that created by the 1958 Lituya Bay landslide, a poorly recorded (by modern standards) event that is nonetheless the most important dataset for understanding extreme landslide tsunami hazards available to the engineering community. This project supports an interdisciplinary, coastal impact investigation of the tsunami generated by the Taan Fjord landslide. The aim of survey is to record runup measurements and tsunami impacts throughout Taan Fjord and Icy Bay. In the context of hazard mitigation, a record of the tsunami behavior is of paramount importance, and would assist in resolving many questions, for example: How far away from potential landslides does infrastructure need to be located How close can liquefied natural gas (LNG) facilities, as are being proposed throughout western Canada and Alaska, be to landslide sources What about the hazard to existing marinas, harbors, and ports, and the many cruise ships that regularly travel through fjord systems The data to be recorded will be essential to the proper specification of the landslide source and its tsunamigenic potential.From preliminary simulations and early reconnaissance trips, we expect there to be widespread areas where the tsunami runup exceeds 100 meters in elevation, with a gradual, but very localized attenuation of wave height as the tsunami traveled through and out of Taan Fjord. Owing to the extreme runup and inundation distances, as well as the remote location, the team will use a high-accuracy Real Time Kinematic (RTK) survey system, which we expect will yield 10-cm accuracy location elevations, after the data is tide-corrected. The types of data to be collected include the most-important runup elevations, flow depth profiles, areas of sediment scour and deposition, debris piles, and the impact of the tsunami on various types of vegetation. The data from this survey, once processed, will be provided freely to all members of the engineering community. In particular, Lynett's involvement with tsunami hazard mapping in western States, his participation in the National Tsunami Hazard Mitigation Program (NTHMP), and existing collaborations with others studying landslide tsunamis indicates that this data will be folded into ongoing hazard studies immediately.

2015年10月17日，位于阿拉斯加东南部冰湾的塔恩峡湾发生了数十年来北美最大规模的山体滑坡。山体滑坡引发了当地巨大的海啸。来自卫星图像的流量指示器显示，紧邻滑坡体的海啸最大上升高度超过190米。这样的最大上升速度将仅次于1958年利图亚湾山体滑坡造成的海啸，那次事件记录不佳(以现代标准衡量)，但对于工程界了解极端海啸危险来说，这仍然是最重要的数据集。该项目支持对Taan Fjord山体滑坡引发的海啸进行跨学科的沿海影响调查。调查的目的是记录整个塔安峡湾和冰湾的助跑测量和海啸影响。在减灾的背景下，海啸行为的记录是至关重要的，并将有助于解决许多问题，例如：基础设施需要距离潜在的山体滑坡多远，加拿大西部和阿拉斯加正在提议的液化天然气(LNG)设施与山体滑坡源有多近？对现有的码头、港口和港口以及经常通过峡湾系统的许多游轮的危害如何？要记录的数据将对正确确定山体滑坡源及其引发海啸的可能性至关重要。从初步模拟和早期侦察旅行来看，我们预计会有很多地区的海啸高度超过100米，随着海啸穿过和离开塔安峡湾，海浪高度会逐渐衰减，但非常有限。由于极端的拉升和淹没距离，以及偏远的位置，该小组将使用高精度的实时动态(RTK)测量系统，我们预计在数据经过潮汐校正后，该系统将产生10厘米精度的位置高程。要收集的数据类型包括最重要的抬升高度、水流深度剖面、沉积物冲刷和淤积区域、碎屑堆，以及海啸对各种植被的影响。这项调查的数据经过处理后，将免费提供给工程界的所有成员。特别是，Lynett参与了西部各州的海啸危险测绘，他参与了国家海啸减灾计划(NTHMP)，以及与其他研究滑坡海啸的人现有的合作表明，这些数据将立即纳入正在进行的危险研究。