Bathymetry of Lake Ontario

Bathymetry of Lake Ontario has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more accessible to the public. The project is a cooperative effort between investigators at the NOAA National Geophysical Data Center's Marine Geology & Geophysics Division (NGDC/MGG) and the NOAA Great Lakes Environmental Research Laboratory (GLERL). was compiled utilizing the entire historic sounding data base. The entire historic hydrographic sounding data base from the U.S. and Canada, originally collected for nautical charting purposes, was used to create a complete and accurate representation of Lake Ontario bathymetry. The U.S. data primarily came from the NOS Hydrographic Survey Data. This and other bathymetric sounding data collected by the U.S. National Ocean Service's (NOS) Coast Survey and the U. S. Army Corps of Engineers was employed to construct bathymetric contours at 1 meter intervals from 1-10 meters depth and 2 meter intervals at depths greater than 10 meters. Compilation scales ranged from 1:10,000 to 1:50,000. Bathymetric sounding data collected by the Canadian Hydrographic Service (CHS) were employed to construct bathymetric contours at 1 meter intervals and compilation scales ranging from 1:1,000 to 1:30,000. Digitization of the bathymetric contours, merging of the bathymetric contour data sets, poster construction, and preparation of a CD-ROM, were accomplished at the NGDC. Multibeam bathymetric data collected by the University of New Brunswick's Ocean Mapping Group (UNB-OMG), with support of the Geological Survey of Canada (GSC) and the CHS, were kindly made available in gridded form. In the two areas where multibeam bathymetric data were available, no other bathymetric data were used in the compilations. In some areas all available Canadian and U. S. bathymetric sounding data, collected at different times on different survey expeditions, were used to derive the contours. The U.S. coastline used was primarily the GLERL Medium Resolution Vector Shoreline dataset (Lee, 1998). Where needed for more coverage, the NOS Medium Resolution Vector Shoreline for the Conterminous U.S. (1994) dataset was used. Coastlines from the CHS bathymetric sounding data field sheets were used to complete the Canadian coastline. Images were constructed using the publicly-available software Generic Mapping Tools (GMT).

安大略湖（Lake Ontario）湖底水深地形数据作为美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration，NOAA）项目的组成部分完成汇编，该项目旨在挽救五大湖湖底地质与地球物理数据，并提升其面向公众的可获取性。本项目由NOAA国家地球物理数据中心海洋地质与地球物理分部（National Geophysical Data Center's Marine Geology & Geophysics Division，NGDC/MGG）与NOAA大湖环境研究实验室（Great Lakes Environmental Research Laboratory，GLERL）的研究人员合作开展，本次水深地形数据汇编依托全部历史测深数据库完成。用于构建安大略湖完整精准水深地形模型的原始数据，源自美国和加拿大此前专为海图绘制收集的全部历史水文测深数据库。其中，美国方面的数据主要来自美国国家海洋服务局（National Ocean Service，NOS）海道测量调查数据。美国国家海洋服务局海岸调查队与美国陆军工程兵团采集的此类及其他水深测深数据，被用于生成水深等值线：水深1至10米区间采用1米间隔，水深大于10米区间采用2米间隔，本次汇编的比例尺范围为1:10000至1:50000。加拿大水文局（Canadian Hydrographic Service，CHS）采集的水深测深数据，则被用于生成1米间隔的水深等值线，汇编比例尺范围为1:1000至1:30000。NGDC完成了水深等值线数字化、水深等值线数据集合并、样图制作以及只读光盘（CD-ROM）制备工作。由纽布伦斯威克大学海洋制图小组（University of New Brunswick's Ocean Mapping Group，UNB-OMG）采集，并获得加拿大地质调查局（Geological Survey of Canada，GSC）与CHS支持的多波束水深地形数据，已以网格化形式公开提供。在存在多波束水深地形数据的两处区域，本次汇编未使用其他任何水深数据。在部分区域，所有可获取的加拿大与美国不同时期、不同勘测航次采集的水深测深数据，均被用于推导等值线。本次采用的美国海岸线数据主要源自GLERL中等分辨率矢量岸线数据集（Lee, 1998），若需补充覆盖范围，则使用美国本土NOS中等分辨率矢量岸线（1994）数据集。加拿大海岸线则通过CHS水深测深数据野外记录表中的岸线信息完成补全。图像通过公开可用软件通用制图工具（Generic Mapping Tools，GMT）制作完成。