Enhanced TIFF Sidescan-Sonar Mosaic East of Virgin Basin - Lake Mead, Nevada: Geographic Coordinates
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Metadata:
- Identification_Information:
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- Citation:
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- Citation_Information:
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- Originator: David C. Twichell
- Originator: VeeAnn A. Cross
- Publication_Date: 2003
- Title:
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Enhanced TIFF Sidescan-Sonar Mosaic East of Virgin Basin - Lake Mead, Nevada: Geographic Coordinates
- Geospatial_Data_Presentation_Form: remote-sensing image
- Online_Linkage: <https://pubs.usgs.gov/of/2003/of03-320/htmldocs/datacatalog.htm>
- Online_Linkage:
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<https://pubs.usgs.gov/of/2003/of03-320/data/sscanimgs/geographic/enhanced/>
- Online_Linkage:
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<https://pubs.usgs.gov/of/2003/of03-320/data/sscanimgs/geographic/enhanced/tempiceenh_g.tif>
- Online_Linkage:
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<https://pubs.usgs.gov/of/2003/of03-320/data/sscanimgs/geographic/enhanced/tempiceenh_g.tfw>
- Online_Linkage: <https://pubs.usgs.gov/of/2009/1150/gis/sidescan/tempiceeng_g.zip>
- Larger_Work_Citation:
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- Citation_Information:
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- Originator: David C. Twichell
- Originator: VeeAnn A. Cross
- Originator: Stephen D. Belew
- Publication_Date: 2003
- Title:
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Mapping the floor of Lake Mead (Nevada and Arizona): Preliminary discussion and GIS data release
- Series_Information:
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- Series_Name: Open-File Report
- Issue_Identification: 03-320
- Publication_Information:
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- Publication_Place: Woods Hole Field Center, Woods Hole, MA
- Publisher: U.S. Geological Survey
- Online_Linkage: <https://pubs.usgs.gov/of/2003/of03-320/>
- Description:
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- Abstract:
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Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction of Hoover Dam and is one of a series of multi-purpose reservoirs on the Colorado River. The lake extends 183 km from the mouth of the Grand Canyon to Black Canyon, the site of Hoover Dam, and provides water for residential, commercial, industrial, recreational, and other non-agricultural users in communities across the southwestern United States. Extensive research has been conducted on Lake Mead, but a majority of the studies have involved determining levels of anthropogenic contaminants such as synthetic organic compounds, heavy metals and dissolved ions, furans/dioxins, and nutrient loading in lake water, sediment, and biota (Preissler, et al., 1998; Bevans et al, 1996; Bevans et al., 1998; Covay and Leiker, 1998; LaBounty and Horn, 1997; Paulson, 1981). By contrast, little work has focused on the sediments in the lake and the processes of deposition (Gould, 1951). To address these questions, sidescan-sonar imagery and high-resolution seismic-reflection profiles were collected throughout Lake Mead by the USGS in cooperation with researchers from University of Nevada Las Vegas (UNLV). These data allow a detailed mapping of the surficial geology and the distribution and thickness of sediment that has accumulated in the lake since the completion of Hoover Dam. Results indicate that the accumulation of post-impoundment sediment is primarily restricted to former river and stream beds that are now submerged below the lake while the margins of the lake appear to be devoid of post-impoundment sediment. The sediment cover along the original Colorado River bed is continuous and is typically greater than 10 m thick through much of its length. Sediment thickness in some areas exceeds 35 m while the smaller tributary valleys typically are filled with less than 4 m of sediment. Away from the river beds that are now covered with post-impoundment sediment, pre-impoundment alluvial deposits and rock outcrops are still exposed on the lake floor.
- Purpose:
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This sidescan-sonar imagery is used to map the morphology of the lake floor and determine the extent of sediment distribution on the lake floor.
- Supplemental_Information:
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This previously published dataset is provided as a courtesy in Open-File Report 1150 "Surficial Geology of the Floor of Lake Mead (Arizona and Nevada) as Defined by Sidescan-sonar Imagery, Lake Floor Topography and Post-impoundment Sediment Thickness", available online: <https://pubs.usgs.gov/of/2009/1150/>. Improvements have been made to this metadata file even though the originally published data have not been modified.
- Time_Period_of_Content:
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- Time_Period_Information:
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- Range_of_Dates/Times:
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- Beginning_Date: 20010401
- Ending_Date: 20010426
- Currentness_Reference: ground condition
- Status:
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- Progress: Complete
- Maintenance_and_Update_Frequency: None planned
- Spatial_Domain:
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- Bounding_Coordinates:
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- West_Bounding_Coordinate: -114.368843
- East_Bounding_Coordinate: -114.023218
- North_Bounding_Coordinate: 36.205417
- South_Bounding_Coordinate: 36.003054
- Keywords:
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- Theme:
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- Theme_Keyword_Thesaurus: General
- Theme_Keyword: CMGP
- Theme_Keyword: Coastal and Marine Geology Program
- Theme_Keyword: images
- Theme_Keyword: mosaic
- Theme_Keyword: OFR03-320
- Theme_Keyword: Open-File Report
- Theme_Keyword: reservoir
- Theme_Keyword: sidescan
- Theme_Keyword: sidescan sonar
- Theme_Keyword: TIFF
- Theme_Keyword: U.S. Geological Survey
- Theme_Keyword: USGS
- Theme_Keyword: Woods Hole Field Center
- Theme:
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- Theme_Keyword_Thesaurus: ISO 19115 Topic Category
- Theme_Keyword: geoscientificInformation
- Theme_Keyword: imageryBaseMapsEarthCover
- Theme_Keyword: inlandWaters
- Place:
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- Place_Keyword_Thesaurus: General
- Place_Keyword: Arizona
- Place_Keyword: Colorado River
- Place_Keyword: Iceberg Canyon
- Place_Keyword: Lake Mead
- Place_Keyword: Las Vegas
- Place_Keyword: Mojave Desert
- Place_Keyword: Nevada
- Place_Keyword: United States
- Place_Keyword: Virgin Basin
- Place_Keyword: North America
- Access_Constraints: NONE
- Use_Constraints:
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The U.S. Geological Survey must be referenced as the originator of the dataset in any future products or research derived from these data.
- Point_of_Contact:
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- Contact_Information:
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- Contact_Person_Primary:
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- Contact_Person: David C. Twichell
- Contact_Organization: U.S. Geological Survey
- Contact_Position: Oceanographer
- Contact_Address:
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- Address_Type: mailing and physical address
- Address: 384 Woods Hole Rd.
- City: Woods Hole
- State_or_Province: MA
- Postal_Code: 02543-1598
- Contact_Voice_Telephone: (508) 548-8700 x2266
- Contact_Facsimile_Telephone: (508) 457-2310
- Contact_Electronic_Mail_Address: dtwichell@usgs.gov
- Native_Data_Set_Environment:
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Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.2.6.1500
- Cross_Reference:
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- Citation_Information:
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- Originator: H.E. Bevans
- Originator: S.L. Goodbred
- Originator: J.F. Miesner
- Originator: S.A. Watkins
- Originator: T.S. Gross
- Originator: N.D. Denslow
- Originator: T. Choeb
- Publication_Date: 1996
- Title:
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Synthetic organic compounds and carp endocrinology and histology, Las Vegas Wash and Las Vegas and Callville bays of Lake Mead Nevada
- Series_Information:
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- Series_Name: Water-Resources Investigations
- Issue_Identification: 96-4266
- Publication_Information:
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- Publisher: U.S. Geological Survey
- Cross_Reference:
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- Citation_Information:
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- Originator: H.E. Bevans
- Originator: M.S. Lico
- Originator: S.J. Lawrence
- Publication_Date: 1998
- Title:
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Water quality in the Las Vegas Valley area and the Carson and Truckee River basins, Nevada and California, 1992-1996
- Series_Information:
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- Series_Name: Circular
- Issue_Identification: 1170
- Publication_Information:
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- Publisher: U.S. Geological Survey
- Cross_Reference:
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- Citation_Information:
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- Originator: K.J. Couvay
- Originator: T.J. Leiker
- Publication_Date: 1998
- Title:
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Synthetic organic compounds in water and bottom sediment from streams, detention basins, and sewage-treatment plant outfalls in Las Vegas Valley, Nevada, 1997
- Series_Information:
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- Series_Name: Open-File Report
- Issue_Identification: 98-633
- Publication_Information:
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- Publisher: U.S. Geological Survey
- Cross_Reference:
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- Citation_Information:
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- Originator: H.R. Gould
- Publication_Date: 1951
- Title: Some quantitative aspects of Lake Mead turbidity currents
- Series_Information:
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- Series_Name: SEPM Special Publication
- Issue_Identification: No. 2
- Publication_Information:
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- Publisher: Society of Economic Paleontologists and Mineralogists
- Cross_Reference:
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- Citation_Information:
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- Originator: J.F. LaBounty
- Originator: M.J. Horn
- Publication_Date: 1997
- Title:
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The influence of drainage from the Las Vegas Valley on the limnology of Boulder Basin, Lake Mead, Arizona-Nevada
- Series_Information:
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- Series_Name: Journal of Lake and Reservoir Management
- Issue_Identification: v. 13
- Cross_Reference:
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- Citation_Information:
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- Originator: L.J. Paulson
- Publication_Date: 1981
- Title:
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Nutrient management with hydroelectric dams on the Colorado River
- Series_Information:
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- Series_Name: Technical Report
- Issue_Identification: #8
- Publication_Information:
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- Publication_Place:
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Department of Biological Sciences, University of Nevada, Las Vegas, Nevada
- Publisher: Lake Mead Limnological Research Center
- Cross_Reference:
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- Citation_Information:
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- Originator: A.M. Preissler
- Originator: G.A. Roach
- Originator: K.A. Thomas
- Originator: J.W. Wilson
- Publication_Date: 1998
- Title: Water resources data, Nevada, water year 1998
- Series_Information:
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- Series_Name: Water Resources Data Nevada
- Issue_Identification: NV-98-1
- Publication_Information:
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- Publisher: U.S. Geological Survey
- Data_Quality_Information:
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- Logical_Consistency_Report:
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All these data were collected with the same sidescan-sonar towfish. The majority of the data comprising this mosaic was acquired at a 1500m total swath width. In some small areas, data gaps were filled with data collected at a 750m total swath width. However, in each case, the data were resampled to a 2 m pixel size.
- Completeness_Report: All imagery necessary to map the lake floor was used.
- Positional_Accuracy:
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- Horizontal_Positional_Accuracy:
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- Horizontal_Positional_Accuracy_Report:
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The ship was navigated with P-CODE GPS. The towfish was deployed at approximately the same depth each day, with little variation during the course of the survey. Therefore range to fish values are assumed consistent and accurate.
- Lineage:
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- Process_Step:
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- Process_Description:
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Sidescan sonar imagery was collected using a Datasonics SIS-1000 sidescan sonar system and logged to a Triton QMIPS data logging computer.
- Process_Step:
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- Process_Description:
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The digital sidescan data were then processed and mapped to provide proper geographic locations of features identified in the imagery. The processing steps included subsampling the raw sidescan data using a median filtering routine to suppress speckle noise and reduce file size, and correct for slant-range distortion, signal attenuation, and dropped sonar lines using XSonar (Danforth et al., 1991). After these processing steps, the imagery was mapped into its proper geographic location using techniques summarized by Paskevich (1996). Individual sidescan swaths were mapped with each pixel geographically positioned at a resolution of 2 m/pixel.
Due to the difficult nature of working in a lake environment, XSonar was modified by Danforth to incorporate the ability to exclude portions of the imagery from the beam angle correction routine. This enabled the stark contrast between highly reflection rock outcrops and fine-grained sediment deposits to be preserved. This enhancement was not available in 2001 when the data were collected, so the data were reprocessed in 2001. Processing the data up to this point was done be VeeAnn Cross.
- Source_Used_Citation_Abbreviation:
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Danforth, W.W., O'Brien, T.F., and Schwab, W.C., 1991, USGS image processing system: near real-time mosaicking of high-resolution sidescan-sonar data: Sea Technology, Jan., 1991, p. 54-59.
- Source_Used_Citation_Abbreviation:
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Paskevich, V.F., 1996, MAPIT: An improved method for mapping digital sidescan sonar data using the Woods Hole Image Processing System (WHIPS) software: U.S. Geological Survey Open-File Report 96-281, 73p.
- Process_Step:
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- Process_Description:
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Non-overlapping swaths were then brought into the remote sensing software package PCI. The techniques for generating the composite digital sidescan mosaic are summarized by Paskevich (1992). Processing of the data from this point on was done by David C. Twichell.
- Source_Used_Citation_Abbreviation:
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Paskevich, V.F., 1992, Digital mapping of sidescan sonar data with the Woods Hole Image Processing System software: U.S. Geological Survey Open-File Report 92-536, 87p.
- Process_Step:
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- Process_Description:
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Because of the close relationship of the imagery to the topography of the lake, a shaded-relief image generated from the DEM with the 10m contours burned into it was imported to PCI and the sidescan-sonar image strips were georeferenced to it. Misalignments based on the ground control points that were selected between the sidescan-sonar imagery and the DEM after georeferencing were less than 20m in all areas of the lake except a small section of Black Canyon and part of Boulder Canyon.
- Process_Step:
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- Process_Description:
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The mosaic then had a linear stretch applied to the data to reduce the valid data range from 0-255 to 0-254. When mapped on a white background, the background can be made transparent in the GIS without affecting the data.
- Process_Step:
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- Process_Description:
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Once the mosaics were completed, noise and areas of no data were trimmed from the fringes of the completed mosaic. The lake shoreline as defined by the U.S. Bureau of Reclamation was used to trim noise and nodata areas that fell beyond the limits of the lake.
- Process_Step:
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- Process_Description:
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A root stretch was applied in PCI to the sidescan image to help enhance the features. The root stretch was from 15-220 with resulting values between 0 and 254. This was done so that the white background (255) could be made transparent in the GIS.
- Process_Step:
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- Process_Description:
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The UTM projected image was the reprojected to Geographic coordinates using BlueMarble's Geographic Transformer software. Transform parameters used a resolution of 2m/pixel and a central latitude of 36N.
- Spatial_Data_Organization_Information:
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- Direct_Spatial_Reference_Method: Raster
- Raster_Object_Information:
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- Raster_Object_Type: Pixel
- Row_Count: 11227
- Column_Count: 15513
- Vertical_Count: 1
- Spatial_Reference_Information:
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- Horizontal_Coordinate_System_Definition:
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- Geographic:
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- Latitude_Resolution: 0.000018
- Longitude_Resolution: 0.000022
- Geographic_Coordinate_Units: Decimal degrees
- Geodetic_Model:
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- Horizontal_Datum_Name: D_WGS_1984
- Ellipsoid_Name: WGS_1984
- Semi-major_Axis: 6378137.000000
- Denominator_of_Flattening_Ratio: 298.257224
- Entity_and_Attribute_Information:
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- Overview_Description:
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- Entity_and_Attribute_Overview:
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The pixel value represents the DN return value of the sidescan-sonar system. A high value (ie 254) indicates a highly reflective lake floor surface, while a low value (ie 0) indicates low reflectance.
- Distribution_Information:
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- Distributor:
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- Contact_Information:
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- Contact_Person_Primary:
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- Contact_Person: David C. Twichell
- Contact_Organization: U.S. Geological Survey
- Contact_Position: Oceanographer
- Contact_Address:
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- Address_Type: mailing and physical address
- Address: 384 Woods Hole Rd.
- City: Woods Hole
- State_or_Province: MA
- Postal_Code: 02543-1598
- Contact_Voice_Telephone: (508) 548-8700 x2266
- Contact_Facsimile_Telephone: (508) 457-2310
- Contact_Electronic_Mail_Address: dtwichell@usgs.gov
- Resource_Description: Downloadable Data
- Distribution_Liability:
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Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. 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:
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- Digital_Form:
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- Digital_Transfer_Information:
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- Format_Name: WinZip
- Format_Version_Number: 9.0
- Format_Information_Content:
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The WinZip file contains the sidescan-sonar GeoTIFF image as well as the TIFF world file and FGDC metadata.
- Transfer_Size: 16.3 MB
- Digital_Transfer_Option:
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- Offline_Option:
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- Offline_Media: CD-ROM
- Recording_Capacity:
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- Recording_Density: 650
- Recording_Density_Units: MBytes
- Recording_Format: UDF
- Fees: None.
- Technical_Prerequisites:
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The user must be capable of uncompressing the WinZip file. In addition, to view the TIFF image spatially, the user must have software that is capable of reading the GeoTIFF header information, or alternatively, read the TIFF world file spatial reference information.
- Metadata_Reference_Information:
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- Metadata_Date: 20090804
- Metadata_Contact:
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- Contact_Information:
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- Contact_Person_Primary:
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- Contact_Person: VeeAnn A. Cross
- Contact_Organization: U.S. Geological Survey
- Contact_Position: Marine Geologist
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 384 Woods Hole Rd.
- City: Woods Hole
- State_or_Province: MA
- Postal_Code: 02543-1598
- Contact_Voice_Telephone: (508) 548-8700 x2251
- Contact_Facsimile_Telephone: (508) 457-2310
- Contact_Electronic_Mail_Address: vatnipp@usgs.gov
- Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
- Metadata_Standard_Version: FGDC-STD-001-1998
- Metadata_Time_Convention: local time
- Metadata_Extensions:
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- Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
- Profile_Name: ESRI Metadata Profile
Generated by mp version 2.9.6 on Tue Aug 04 15:07:16 2009