Remotely Triggered Slope Failures and Turbidity Currents on the Cascadia Margin

GSTDTAP

项目编号	1634095
	Remotely Triggered Slope Failures and Turbidity Currents on the Cascadia Margin
	Harlan Johnson
主持机构	University of Washington
项目开始年	2016
	2016-09-01
项目结束日期	2018-08-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	362105(USD)
国家	美国
语种	英语
英文摘要	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.
来源学科分类	Geosciences - Ocean Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/70254
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Harlan Johnson.Remotely Triggered Slope Failures and Turbidity Currents on the Cascadia Margin.2016.