08016_Chirp_100SHT.SHP: Shot point navigation at 100-shot intervals collected by the U.S. Geological Survey within the St. Clair River between Michigan and Ontario, Canada, 2008 (ESRI VECTOR SHAPEFILE)

In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.

2008年，美国地质调查局（U.S. Geological Survey, USGS）与伍兹霍尔海岸与海洋科学中心（Woods Hole Coastal and Marine Science Center, WHCMSC）协同美国陆军工程兵团，对密歇根州休伦港与加拿大安大略省萨尼亚市之间的圣克莱尔河上游河床开展了地球物理勘探与采样调查。本次调查旨在明确圣克莱尔河的第四纪地质框架，以评估河床形态变化与下伏地层之间的耦合关系。本报告呈现了2008年5月29日至6月6日期间，作为“国际上五大湖上游研究计划”（International Upper Great Lakes Study）一部分，从圣克莱尔河采集的地球物理与样本数据。该计划由美加国际联合委员会资助，为期5年，旨在探究圣克莱尔河的物理变化是否影响上五大湖水位、评估苏必利尔湖出水调控方案，并研究气候变化对五大湖水位的潜在影响（http://www.iugls.org）。本文件公开了另一篇报告——美国地质调查局公开文件报告2009-1137中所使用的数据集，该报告详细阐释了该区域的第四纪地质框架。本报告对2008年USGS野外作业2008-016-FA期间，用于绘制圣克莱尔河上游河床形态、表层沉积物分布及下伏地质特征的一套高分辨率声学与沉积物采样系统进行了说明。本次数据发布还收录了河床的视频与影像资料。后续分析将聚焦于河床底质侵蚀及其对河道形态与几何特征的影响。最终，国际上五大湖上游研究计划将尝试明确圣克莱尔河的物理变化在何处影响水流，进而波及上五大湖水位。