Remotely Triggered Slope Failures and Turbidity Currents on the Cascadia Margin

卡斯卡迪亚边缘远程触发的斜坡破坏和浊流

• 批准号: 1634095
• 负责人: Harlan Johnson
• 金额: $ 36.21万
• 依托单位: University of Washington
• 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 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1634095&HistoricalAwards=false
• 关键词: Remotely; Triggered; Slope; Failures; Turbidity; Remotely; Triggered; Slope; Failures; Turbidity

Convergence of the North American tectonic plate with the Juan de Fuca, Gorda, and Explorer plates creates the Cascadia subduction zone, extending 1100 km from northern California to Canada's Vancouver Island in the Pacific Northwest. Offshore where the tectonic plates meet, a thick wedge of sediment develops. The sediment wedge forms as a result of erosion on land and transport of the sediment away from the coastline, and the wedge is thickened by the compression resulting from the two plates sliding by each other. Recent great earthquakes and tsunamis around the world have heightened the awareness of the natural hazards posed by the processes occurring along the Cascadia margin. Many of these processes are linked to the sediment wedge, particularly the failure of sediment slopes that may lead to landslides and generate local tsunamis. This project will help to identify the processes controlling the initiation of slope failure on the sediment wedge at the Cascadia margin. Understanding the paths and triggers for sediment slope failures is key to unraveling the history of past earthquakes and assessing the associated earthquake, tsunami, and submarine landslide hazards. The project supports the training of graduate and undergraduate students.Preliminary examination of recent temperature, pressure and seismic data returned from the Cascadia Initiative program of Ocean Bottom Seismometer deployments off of the Cascadia subduction zone has shown that slope failures and sediment flows can be triggered not only by local great earthquakes, but also by the seismic waves from distant earthquakes, including the 2012 Mw8.6 event off the coast of Sumatra. If this interpretation is substantiated by further processing and interpretation of the related data during this project, it will have a major impact on several current scientific issues, including (1) identification of megathrust earthquake recurrence intervals, (2) the amplification of surface seismic shaking by the thick sediments in the accretionary margin wedge, and (3) the transfer of organic carbon within sediment debris flows that originate on the shallow continental shelf and end with burial in the abyssal plain, a key marine component of the global carbon cycle. The end product of the project will be a new model to identify sections of the Cascadia margin that may be prone to slope failures.

北美构造板与胡安·德福卡（Juan de Fuca），戈达（Gorda）和探险家板的汇合创建了卡斯卡迪亚俯冲带，从北加州到西北太平洋的加拿大温哥华岛1100公里。 构造板相遇的近海，会出现浓密的沉积物。 由于在海岸线上侵蚀和沉积物的运输在土地上侵蚀和运输，因此楔形楔形成，楔形被两个板彼此滑动的压缩所产生的增厚。全世界最近的巨大地震和海啸提高了对卡斯卡迪亚边际沿岸发生的过程所带来的自然危害的认识。 这些过程中的许多过程与沉积物楔有关，尤其是可能导致滑坡并产生局部海啸的沉积物斜坡的失败。 该项目将有助于确定控制Cascadia边际沉积物楔子上斜率失败的过程。了解沉积物斜率故障的路径和触发因素是揭示过去地震历史并评估相关地震，海啸和海底滑坡危害的关键。 该项目支持研究生和本科生的培训。对最近的温度，压力和地震数据从卡斯卡迪亚倡议计划中返回的近期温度，压力和地震数据进行了研究，从卡斯卡迪亚俯冲区域部署了海洋底部的地震计部署计划，这表明斜坡故障和沉积物流量不仅可以由当地的沿海地区触发，而且还可以由遥远的地球造成，包括遥远的地球，包括距离的次数，包括2012年的地球，包括距离越过的地球，包括越来越多的地球，这些潮流的潮流也包括在内。苏门答腊。 如果通过在该项目期间对相关数据的进一步处理和解释来证实这种解释，它将对当前的几个科学问题产生重大影响，包括（1）识别巨型地震复发间隔，（2）（2）（2）（2）厚度的厚底沉积物在积分范围内的厚度和（3）在积分范围内的厚度，（3）有机化的carbone carbon的转化，（3）最后是埋葬在深渊平原上，这是全球碳循环的关键海洋组成部分。该项目的最终产品将是一个新模型，以确定可能容易出现斜坡故障的卡斯卡迪亚利润。