Seafloor Geodesy Using Sidescan Sonar: Analysis of the NGDC Archive

GSTDTAP

项目编号	1536386
	Seafloor Geodesy Using Sidescan Sonar: Analysis of the NGDC Archive
	David Sandwell
主持机构	University of California-San Diego Scripps Inst of Oceanography
项目开始年	2015
	2015-09-01
项目结束日期	2017-08-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	200215(USD)
国家	美国
语种	英语
英文摘要	The main objective of the project is to develop a method to use existing multibeam sonars, available on NSF-sponsored research vessels, to measure small displacements of the seafloor associated with rapid events such as earthquakes and landslides. The seafloor displacements are measured by comparing the location of a patch of seafloor surveyed at two times spanning an event. The published accuracy of this approach is currently tens of meters which severely limits the utility of the method. The planned work would greatly improve the accuracy to better than 1 m by collecting data at a slow ship speed and navigating the repeat track to closely follow the reference track. This order of magnitude improvement in displacement accuracy would provide a valuable tool for assessing and understanding large and sometimes-destructive seafloor events. Broader impacts include improvements to the system software that will be freely available to others. Funding includes the training of a graduate student in the methods of high-resolution sonar and seafloor geodesy. The project will develop a method to use existing multibeam sonars, available on NSF-sponsored research vessels, to measure small displacements of the seafloor associated with rapid events such as earthquakes and landslides. The seafloor displacements are measured by differencing the location of a patch of seafloor surveyed at two times spanning an event. The published accuracy of this approach is currently tens of meters which severely limits the utility of the method. This work would greatly improve the accuracy to better than 1 m by collecting data at a slow ship speed and navigating the repeat track to closely follow the reference track. This order of magnitude improvement in displacement accuracy would provide a valuable tool for assessing and understanding large and sometimes-destructive seafloor events. The proposal addresses one of the eight high-level science questions posed in the recent National Research Cpuncil Decadal Report (NRC, 2015), i.e., how can risk be better characterized and the ability to forecast geohazards like mega-earthquakes, tsunamis, undersea landslides, and volcanic eruptions be improved? The tools of GPS and InSAR are used to monitor the crustal deformation onshore of the Cascadia Subduction Zone but most of the locked part of the megathrust interface lies offshore. While the PI?s method does not have sufficient accuracy to monitor interseismic motions, it can serve as a pre-event survey of the surface trace similar to the San Andreas Fault B-4 lidar survey.
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/68638
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	David Sandwell.Seafloor Geodesy Using Sidescan Sonar: Analysis of the NGDC Archive.2015.