Interpretive Data Layer Showing Distribution of Modern Features Within National Oceanic and Atmospheric Adminitration (NOAA) Survey H11250 (H11250G_MOD, Geographic)

The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. The current phase of this research program is directed toward studies of sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology. Acoustic data collected during hydrographic surveys provide valuable base maps for marine geological interpretations. These maps help define the geological variability of the seafloor (one of the primary controls of benthic habitat diversity); improve our understanding of the processes that control the distribution and transport of bottom sediments, and the distribution of benthic habitats and associated infaunal community structures; and provide a detailed framework for future research, monitoring, and management activities.
This shapefile represents the interpretation of modern processes and features found on the bathymetric data set of study area H11250, The Race. Sharing of multibeam bathymetric data (NOAA Ship Thomas Jefferson, October 2003 survey H11250) between NOAA's Atlantic Hydrographic Branch and the State of Connecticut/USGS Geologic Mapping Cooperative has yielded a new geologic perspective on approximately 93.75 km2 of the sea floor in the vicinity of The Race, an area where the Orient Point-Fishers Island segment of the Harbor Hill-Roanoke Point-Orient Point-Fishers Island-Charlestown Moraine marks the dividing line between easternmost Long Island Sound and northwestern Block Island Sound. The detailed bathymetry collected by NOAA has been examined in relation to seismic data collected concurrently, as well as archive data collected as part of a long-standing geologic mapping partnership between the State of Connecticut and the U.S. Geological Survey (USGS). These new data reveal previously unknown details of the physical character of the sea floor such as bedforms, moraines, and ship wrecks. These features have been mapped as interpretive GIS data layers that can be used in conjunction with the multibeam grid H11250G or related shaded relief graphics (h11250gcolhs.tif).

美国地质调查局（U.S. Geological Survey, USGS）与美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）以及康涅狄格州环境保护部合作，对长岛海湾（Long Island Sound）——这片坐落于美国人口最稠密区域的重要东海岸河口湾——开展了详细的海底地质填图工作。本系列研究基于1982年启动的康涅狄格州合作研究项目推进。本研究计划的当前阶段聚焦于海底沉积物分布、调控沉积物分布的动力过程、近岸环境问题，以及底栖生物群落结构与海底地质的关联。水文测量中采集的声学数据可为海洋地质解译提供宝贵的基础图件：这些图件既可明确海底的地质差异性（这是底栖生境多样性的核心控制因素之一），也能加深我们对调控底沉积物分布与运移、底栖生境及相关底内生物群落结构分布的动力过程的理解，还可为未来的研究、监测与管理活动提供精细的研究框架。
本形状文件（shapefile）是对研究区H11250“海峡航道（The Race）”水深数据集所反映的现代过程与地貌特征的解译成果。NOAA“托马斯·杰斐逊”号调查船于2003年10月开展的H11250测量所获取的多波束水深数据，经NOAA大西洋水文分支与康涅狄格州/USGS地质填图合作项目组共享后，为“海峡航道”周边约93.75平方千米的海底带来了全新的地质解译视角。该区域的分界线为Harbor Hill-Roanoke Point-Orient Point-Fishers Island-Charlestown冰碛带的Orient Point-Fishers Island段，分隔了最东端的长岛海湾与西北侧的布洛克岛海峡。研究人员结合同步采集的地震数据，以及康涅狄格州与USGS长期地质填图合作项目中的存档数据，对NOAA采集的精细水深数据进行了解译。这些新数据揭示了此前未被发现的海底物理特征细节，包括沉积底形、冰碛物与沉船。上述特征已被解译为GIS数据图层，可与多波束网格H11250G或相关晕渲地形图（h11250gcolhs.tif）配合使用。