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. Anthropogenic wastes, toxic chemicals, and changes in land-use patterns resulting from residential, commercial, and recreational development have stressed the environment of the Sound, causing degradation and potential loss of benthic habitats (Koppelman and others, 1976; Long Island Sound Study, 1994). Detailed maps of the sea floor are needed to help evaluate the extent of adverse impacts and to help manage resources wisely in the future. Therefore, in a continuing effort to better understand Long Island Sound, we have constructed and interpreted sidescan sonar mosaics (complete-coverage acoustic images of the sea floor) within specific areas of special interest. The mosaic presented herein covers almost 300 km square area of the sea floor in west-central Long Island Sound off Milford, Connecticut. The mosaics and their interpretations (represented in part by this data layer) serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving 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 (3) providing a detailed framework for future research, monitoring, and management activities. The sidescan sonar mosaics also serve as base maps for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretation of point measurements.
Purpose:
This data layer is a component of the Milford / West-Central Survey, Long Island Sound, GIS database and represents an interpretation of the sidescan sonar mosaic for the study area. The interpretation can be used as an overlay for the mosaic image and shows the sedimentary environments of the study area such as erosion or nondeposition, coarse-grained transport, sorting and reworking, and deposition. This layer can be used in conjunction with layers: h11044seddist.shp, h11044int.shp, and images h11044_geo_wgs84_enhan.tif and h11044_geo_wgs84.tif.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2001
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -73.131256
East_Bounding_Coordinate: -72.936531
North_Bounding_Coordinate: 41.242020
South_Bounding_Coordinate: 41.023193
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: CMGP
Theme_Keyword: National Oceanic and Atmospheric Administration
Theme_Keyword: NOAA
Theme_Keyword: Woods Hole Science Center
Theme_Keyword: WHSC
Theme_Keyword: NOAA Ship RUDE
Theme_Keyword: ArcGIS
Theme_Keyword: sidescan sonar interpretation
Theme_Keyword: Long Island Sound Resource Center
Theme_Keyword: sedimentary environments
Theme_Keyword: erosion
Theme_Keyword: deposition
Theme_Keyword: sediment transport
Theme_Keyword: Holocene
Theme_Keyword: Quaternary
Theme_Keyword: polygon shapefile
Theme_Keyword: Open-File Report 2005-1018
Theme_Keyword: OFR 2005-1018
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: oceans and estuaries
Theme_Keyword: oceans and estuaries
Theme_Keyword: geoscientificInformation
Place:
Place_Keyword_Thesaurus: General
Place_Keyword: Long Island Sound
Place_Keyword: Connecticut
Place_Keyword: U.S. East Coast
Place_Keyword: Milford
Place_Keyword: Lordship
Place_Keyword: Stratford Shoal
Place_Keyword: Middle Ground
Place_Keyword: North America
Place_Keyword: United States
Place_Keyword: Atlantic Ocean
Place_Keyword: North Atlantic Ocean
Place_Keyword: northeast United States
Temporal:
Access_Constraints: None
Use_Constraints:
Public domain data are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration, and Long Island Sound Resource Center as the originators of this dataset.
Overview image showing the interpretation of the sedimentary environment of NOAA H11044 sidescan sonar mosaic.
Browse_Graphic_File_Type: GIF
Data_Set_Credit:
The U.S. Geological Survey (USGS), National Oceanic and Atmospheric Administration (NOAA), and Long Island Sound Resource Center must be acknowledged as the originators of this data set.
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.0.0.535
Cross_Reference:
Citation_Information:
Originator: K.Y. McMullen
Originator: L.J. Poppe
Originator: M.L. DiGiacomo-Cohen
Originator: M.S. Moser
Originator: E.B. Christman
Publication_Date: 2005
Title:
Surficial Geology of the Sea Floor in West-Central Long Island Sound as shown by Sidescan Sonar Imagery
Edition: 1.0
Series_Information:
Series_Name: Northeastern Geology and Environmental Sciences
Issue_Identification: v. 27, no. 1, p. 60-70
Publication_Information:
Publication_Place: Lawrence, Kansas
Publisher: Allen Press
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report: Attributes have been visually checked by the compilers.
Logical_Consistency_Report:
Several shapefiles representing various features identified on the mosaic were combined to create this data layer. The layers were edited and processed in a consistent manner.
Completeness_Report: Layer is complete as interpreted for these features.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Navigation was by differential GPS; positional accuracy to less than 10 m.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Originator: National Oceanic and Atmospheric Administration
Modified sidescan sonar mosaic (originally created by National Oceanic and Atmospheric Administration (NOAA). The sonar image was visually interpreted to create this data layer.
Process_Step:
Process_Description:
The sidescan sonar imagery was interpreted to create the shapefiles representing the sedimentary environments (erosion or nondeposition, coarse-grained transport, sorting and reworking, and deposition).
The shapefiles were converted to ArcGIS coverage format, combined, edited, and cleaned (for content and consistent topology). A single study area boundary was edited and used for all associated data layers. Polygons and arcs were attributed.
Source_Used_Citation_Abbreviation: shapefiles listed in previous step
Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Shape
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: AREA
Attribute_Definition: Area of feature in internal units squared.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Positive real numbers that are automatically generated.
Attribute:
Attribute_Label: PERIMETER
Attribute_Definition: Perimeter of feature in internal units.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Positive real numbers that are automatically generated.
Attribute:
Attribute_Label: H11044SED_
Attribute_Definition:
ArcInfo internal feature id. Field has no applicable relevance to the data.
Attribute_Definition_Source: USGS
Attribute:
Attribute_Label: H11044SED1
Attribute_Definition:
ArcInfo internal feature id. Field has no applicable relevance to the data.
Attribute_Definition_Source: USGS
Attribute:
Attribute_Label: SEDENVIRON
Attribute_Definition:
interpretation of sidescan sonar mosaic's sedimentary environments
Attribute_Definition_Source: compiler
Attribute_Domain_Values:
Unrepresentable_Domain: Character String
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: erosion or nondeposition
Enumerated_Domain:
Enumerated_Domain_Value: coarse-grained sediment transport
Enumerated_Domain:
Enumerated_Domain_Value: sorting and reworking
Enumerated_Domain:
Enumerated_Domain_Value: deposition
Overview_Description:
Entity_and_Attribute_Overview:
Polygons are attributed as features based on the interpretation of the sidescan sonar mosaic's sedimentary environments (erosion or nondeposition, coarse-grained transport, sorting and reworking, and deposition).
Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Lawrence J. Poppe
Contact_Organization: U.S. Geological Survey
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: (508) 548-8700 x2314
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: lpoppe@usgs.gov
Resource_Description: Downloadable Data
Distribution_Liability:
Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: SHP
Format_Version_Number: ArcView 3.3
Format_Specification: ESRI shapefile
Format_Information_Content:
The SHP file contains the geospatial data. The SHX file contains the index of the geospatial data. The DBF file contains the attribute data in dBase format. The PRJ file contains the coordinate system information (optional). The AVL file contains the legend information (optional). The SBN and SBX files contain the spatial index of the geospatial data (optional). The XML file contains the metadata describing the data set <data set name>.shp.xml. An ASCII version of the metadata file. A browse graphic showing the data layer coverage and extent (optional).
File_Decompression_Technique: no compression applied
These data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS® or ArcView® 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of the importing data. A free data viewer, arcexplorer, capable of displaying the data is available from ESRI at www.esri.com.
Available_Time_Period:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2005
Metadata_Reference_Information:
Metadata_Date: 20050805
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: L.J. Poppe
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: U.S. Geological Survey
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: USA
Contact_Voice_Telephone: (508) 548-8700 x2314
Contact_Electronic_Mail_Address: lpoppe@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
