1998 seismic shotpoint navigation at 100 shot intervals off the coast of Washington and Oregon (geographic coordinates)

Two 21-day field operations were conducted in 1997 and 1998 in the estuaries and on the inner continental shelf off the northern Oregon and southern Washington coast. These cruises aboard the R/V Corliss were run in order to generate reconnaissance maps of the seafloor geology and the shallow subsurface stratigraphy using sidescan sonar and seismic-reflection mapping techniques. The 1998 cruise also collected sediment grab samples, bottom photographs, and video images to verify the sidescan-sonar imagery and to document the seafloor geology. The combination of these data with previously collected sediment sample data (Robert, 1974; Nittrouer, 1978; and Smith et. al., 1980) has been used to define the extent and lithology of shelf sediments associated with the Columbia River littoral cell. This work is one component of a larger project studying the erosion of the Washington and Oregon coast and is being coordinated by the U.S. Geological Survey and the Washington State Department of Ecology. The reason for collecting these data is to provide a regional synthesis of the offshore geology to support a wide variety of management decisions and to provide a basis for further process-oriented investigations.

1997年与1998年，科研团队在俄勒冈州北部及华盛顿州南部海岸外的河口区域与内陆陆架开展了两次为期21天的野外作业。两次航行均由“科利斯号”科考船（R/V Corliss）搭载执行，旨在利用侧扫声呐（sidescan sonar）与地震反射测绘技术，绘制海底地质与浅层地下地层的普查图件。1998年的航行还同步采集了沉积物抓取样品、海底照片与视频影像，用于验证侧扫声呐成像结果并记录海底地质特征。将本次采集数据与此前已获取的沉积物样品数据（Robert，1974；Nittrouer，1978；Smith等，1980）相结合，可明确与哥伦比亚河沿岸带（Columbia River littoral cell）相关的陆架沉积物分布范围与岩性特征。本项研究是华盛顿州与俄勒冈州海岸侵蚀综合研究项目的子课题之一，由美国地质调查局（U.S. Geological Survey）与华盛顿州生态部（Washington State Department of Ecology）联合协调推进。本次数据采集的核心目的在于构建近海地质的区域综合数据集，为各类海洋管理决策提供支撑，并为后续过程导向型研究奠定基础。