NOAA Coastal Services Center 20000531 One Map Charleston, South Carolina, USA NOAA Coastal Services Center This data layer was created from the Geophysical Data System (GEODAS)data sets compiled by the National Geophysical Data Center (NGDC) from NOAA hydrographic surveys. NOAA Coastal Services Center 20000531 Charleston, South Carolina, USA NOAA Coastal Services Center <http://www.csc.noaa.gov/cgi-bin/crs/BouncePage.cgi?Bounce2=ftp://www.csc.noaa.gov/pub/lcr/nyharbor/changelb.zip&product=232> The Bathymetric Change Grid of Lower Bay, New York was created for use in the Sediment Profile Imaging for New York/New Jersey Harbor for October 1994 to October 1995 project. Hydrographic survey data were brought into Environmental Systems Research Institute (ESRI), Inc. ArcView geographic information system (GIS) software for visualization. Depth changes were calculated from bathymetric data gathered through the National Ocean Service hydrographic survey from Lower Bay, NY. Changes caused by natural and anthropogenic sources can be assessed through comparisons of historical and more recent information. These data are critical for bathymetric change analysis in Lower Bay, NY. The data layer created from this dataset was used for spatial analysis in the Benthic Habitats of New York/New Jersey Harbor project to estimate changes in bathymetry as a result of natural processes as well as human-induced changes, such as dredging. Grid creation involved mathematical interpolation of values for some cells in the data layer. These cell values were calculated from the measured values of the twelve nearest-neighbor cells. Therefore, this data layer represents an estimate of bathymetric change in Lower Bay, NY. It is the user's responsibility to determine the appropriate application of this data layer. 1934 1982 ground condition Complete None planned -74.287050 -73.880364 40.613228 40.391903 ISO 19115 Topic Category Boundaries 003 GeoscientificInformation 008 ImageryBaseMapsEarthCover 010 Inland Waters 012 Location 013 Oceans 014 PlanningCadastre 015 None Bathymetry Bathymetric data Depth Geographic Information Systems GIS Grid None Lower Bay Raritan Bay Sandy Hook Bay New York New Jersey New York Harbor Northeast None It is the user's responsibility to determine the appropriate use of this data layer. NOAA Coastal Services Center Landscape Characterization and Restoration (LCR) Program Manager mailing and physical address

2234 South Hobson Avenue

Charleston South Carolina 29405 USA 843-740-1200 843-740-1224 csc@csc.noaa.gov Monday-Friday, 8am-5pm, Eastern Standard Time ESRI Grid format r:\LCR\linda\ny_cd\gis\grids\changelb No formal tests were performed. The accuracy was tested by comparison of calculated depth values to knowledge of historical depths resulting from dredging activities. N/A These data are believed to be complete within the area of interest. All data available from 1934, 1979 and 1982 surveys that occurred within Lower Bay, NY were included in grid creation. The data were retrieved from the GEODAS database with latitude/longitude coordinates in decimal degrees referenced to the North American Datum of 1927 (NAD 27). These data were then converted into North American Datum of 1983 (NAD 83) using ArcView's NADCON extension and projected into Universal Transverse Mercator (UTM) Zone 18 prior to grid creation. The data were referenced to mean low water (MLW) or mean lower low water (MLLW) at the time of collection, depending on the survey. Therefore, there is a vertical offset on the order of one meter which should be considered by the user of these data. NOAA National Environmental Satellite, Data, and Information Service (NESDIS) 199312 Volume 1, Version 3.2 tabular digital data Boulder, Colorado NOAA National Geophysical Data Centers (NGDC), Marine Geology and Geophysics Division <http://www.ngdc.noaa.gov/mgg/> CD-ROM 1934 1934 ground condition NGDC The GEODAS CD-ROM contained the data and retrieval software needed to create this data layer. The data were retrieved from the CD-ROM using the default HYD93 download and tabulated with header information for the oldest and newest bathymetric data with the most comprehensive coverage of the area of interest. The tables were saved as DBF files and brought into ArcView as event themes. They were then converted from NAD 27 to NAD 83 using the NADCON extension and saved as shapefiles. The shapefiles were then projected into UTM Zone 18. Grid interpolation was performed using the Spatial Analyst extension and a mask grid, created from a polygon file of the water and shoreline, was used to produce grids of the oldest and newest bathymetry. This data layer was then created by subtracting the older depth values for each cell from the newer values using the Spatial Analyst extension. NGDC 19990517 NOAA Coastal Services Center Landscape Characterization and Restoration Program (LCR) Program Manager mailing and physical address

2234 South Hobson Avenue

Charleston South Carolina 29405 USA 843-740-1200 843-740-1224 csc@csc.noaa.gov Monday-Friday, 8am-5pm, Eastern Standard Time Raster Grid Cell 477 572 Decimal Degrees North American Datum of 1983 Geodetic Reference System 80 6,378,137 298.257 ArcView Grid raster grid produced by ArcView Spatial Analyst ESRI This data layer is a floating point grid, and therefore it does not have an attribute table or set of attributes. The cell value ranges are based on calculated depths in meters, and negative values represent elevation while positive values represent depth. none NOAA Coastal Services Center Clearinghouse Manager mailing and physical address

2234 South Hobson Avenue

Charleston South Carolina 29405 USA 843-740-1210 843-740-1224 csc@csc.noaa.gov Monday-Friday, 8am-5pm, Eastern Standard Time Bathymetric Change Grid of Lower Bay, NY While every effort has been made to ensure that these data are accurate and reliable within limits of the state of the art, NOAA will not assume any liability for damages caused by any inaccuracies in these data, or failure in their use. For information about obtaining these data, please visit the project home page at <http://www.csc.noaa.gov/cgi-bin/crs/BouncePage.cgi?Bounce2=ftp://www.csc.noaa.gov/pub/lcr/nyharbor/changelb.zip&product=232> 20000412 20000522 NOAA Coastal Services Center Metadata Specialist Mailing and physical address

2234 South Hobson Avenue

Charleston South Carolina 29405 USA 843-740-1200 843-740-1224 csc@csc.noaa.gov Monday-Friday, 8am-5pm, Eastern Standard Time FGDC CSDGM FGDC-STD-001-1998 Generated by mp version 2.2.4 on Mon May 22 14:35:00 2000