Hillshade Surface Representing the Floor of Lake Mead and the surrounding area: Geographic Coordinates 10m cellsize Mr.Sid format
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Metadata:
- Identification_Information:
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- Citation:
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- Citation_Information:
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- Originator: Stephen D. Belew
- Originator: VeeAnn A. Cross
- Publication_Date: 2003
- Title:
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Hillshade Surface Representing the Floor of Lake Mead and the surrounding area: Geographic Coordinates 10m cellsize Mr.Sid format
- Geospatial_Data_Presentation_Form: remote-sensing image
- Online_Linkage:
- 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
- Edition: 1.0
- 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
- 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 GIS (ESRI) grid represents the integration swath bathymetry, on land DEM, and underwater surface derived from countour maps generated pre-impoundment.
- Supplemental_Information:
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Questions regarding the swath bathymetry portion of this dataset should be directed to Steve Belew, while questions regarding the remainder of the dataset and the integration should be directed to VeeAnn Cross.
- 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: 19300000
- Ending_Date: 20011100
- 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: -114.996606
- East_Bounding_Coordinate: -114.003445
- North_Bounding_Coordinate: 36.747196
- South_Bounding_Coordinate: 35.758143
- Keywords:
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- Theme:
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- Theme_Keyword_Thesaurus: General
- Theme_Keyword: ArcView
- Theme_Keyword: bathymetry
- Theme_Keyword: CMGP
- Theme_Keyword: Coastal and Marine Geology Program
- Theme_Keyword: DEM
- Theme_Keyword: digital elevation model
- Theme_Keyword: grid
- Theme_Keyword: images
- Theme_Keyword: lake
- Theme_Keyword: mosaic
- Theme_Keyword: OFR03-320
- Theme_Keyword: Open-File Report
- Theme_Keyword: reservoir
- Theme_Keyword: U.S. Geological Survey
- Theme_Keyword: USGS
- Theme_Keyword: Woods Hole Field Center
- Theme_Keyword: Mr. Sid
- Theme_Keyword: Bureau of Reclamation
- Place:
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- Place_Keyword_Thesaurus: General
- Place_Keyword: Arizona
- Place_Keyword: Black Canyon
- Place_Keyword: Boulder Basin
- Place_Keyword: Colorado River
- Place_Keyword: Gregg Basin
- Place_Keyword: Hoover Dam
- Place_Keyword: Iceberg Canyon
- Place_Keyword: Lake Mead
- Place_Keyword: Las Vegas
- Place_Keyword: Las Vegas Bay
- Place_Keyword: Las Vegas Wash
- Place_Keyword: Mohave Desert
- Place_Keyword: Nevada
- Place_Keyword: Overton Arm
- 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 and Bureau of Reclamation 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: Steve Belew
- Contact_Organization: Bureau of Reclamation
- Contact_Position: GIS Specialist
- Contact_Address:
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- Address_Type: mailing address
- Address: P.O. Box 61470
- City: Boulder City
- State_or_Province: NV
- Postal_Code: 89006-1470
- Country: sbelew@usbr.gov
- Contact_Voice_Telephone: (702) 293-8150
- Native_Data_Set_Environment:
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Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4; ESRI ArcCatalog 8.2.0.700
- 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 endrocrinology 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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- Attribute_Accuracy:
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- Attribute_Accuracy_Report:
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The nature of combining three different datasets tends to reduce the overall accuracy. Therefore a nominal accuracy of 50-100m is assigned to this dataset.
- Logical_Consistency_Report:
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This surface represents the integration of three datasets. One is the swath bathymetry data collected in Lake Mead in November of 2001. The second dataset is the on land DEM acquired from the NED (National Elevation Dataset) project. And the final dataset is the surface generated from pre-impoundment elevation contours as digitized from DRG's of Lake Mead (digital raster graphics). Due to the nature of combining these three different datasets, discrepancies are evident at the bounds of each of the datasets.
- Completeness_Report: This dataset is complete.
- Positional_Accuracy:
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- Horizontal_Positional_Accuracy:
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- Quantitative_Horizontal_Positional_Accuracy_Assessment:
- Vertical_Positional_Accuracy:
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- Quantitative_Vertical_Positional_Accuracy_Assessment:
- Lineage:
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- Process_Step:
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- Process_Description:
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Three sets of data were acquired. The DEM from the area surrounding Lake Mead was acquired from NED (National Elevation Dataset) in 1998. This data was available as 30m/pixel. The swath bathymetry data was collected in Lake Mead during the fall of 2001. Bureau of Reclamation had this data at a very high resolution. The area covered by this surveying is effectively limited to the areas of post-impoundment sediment. The underwater contours available from the DRG's (digital raster graphics) were digitized. These contours were then used to create an underwater surface using the ESRI topogrid command available in Arc/Info. This surface was created with a 10 m/pixel resolution.
- Process_Step:
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- Process_Description:
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The lake bounds shapefile was used to clip the DEM dataset such that all values falling within the lake bounds were turned to NODATA values.
- Process_Step:
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- Process_Description:
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The lake bounds shapefile was used to clip the topogrid dataset such that all values falling outside the lake bounds were turned to NODATA values.
- Process_Step:
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- Process_Description:
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The high-resolution bathymetry data was resampled to a 10 m cellsize using bilinear interpolation.
- Process_Step:
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- Process_Description:
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The swath bathymetry grid was merged with the topogrid surface such that where swath bathymetry data was available, the topogrid surface was overwritten. This provided the present day lakefloor of Lake Mead.
- Process_Step:
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- Process_Description:
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The on land DEM was resampled to a 10 m cellsize grid (super sampling).
- Process_Step:
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- Process_Description:
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This supersampled on land DEM was then combined with the lake floor surface.
- Process_Step:
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- Process_Description:
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The resulting surface then underwent several repetitions of a 4x4 focal mean filtering to remove and null data values and to smooth the transition from one dataset to the next.
- Process_Step:
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- Process_Description:
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This grid surface was then used to generate a hillshade relief image in ArcMap using the default settings.
- Process_Step:
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- Process_Description:
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The ArcInfo command gridimage was used to convert the hillshade grid to a TIFF image.
- Process_Step:
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- Process_Description:
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This TIFF image was then brought into Corel PhotoPaint, version 11, and converted to an 8-bit paletted image and saved with PackBit compression.
- Process_Step:
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- Process_Description:
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This image was then reprojected to the geographic coordinate system using BlueMarble's geographic transformer software. Used a central latitude of 36N.
- Process_Step:
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- Process_Description:
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This TIFF image was then compressed using LizardTech's MrSid Geospatial Encoder version 1.4.
- 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: 10974
- Column_Count: 8915
- 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: 0.00009
- Longitude_Resolution: 0.000111
- Geographic_Coordinate_Units: Decimal degrees
- Planar:
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- Planar_Coordinate_Information:
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- Planar_Coordinate_Encoding_Method: row and column
- Coordinate_Representation:
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- Abscissa_Resolution: 0.000111
- Ordinate_Resolution: 0.000090
- Geodetic_Model:
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- Horizontal_Datum_Name: North American Datum of 1983
- Ellipsoid_Name: Geodetic Reference System 80
- Semi-major_Axis: 6378137.000000
- Denominator_of_Flattening_Ratio: 298.257222
- Entity_and_Attribute_Information:
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- Detailed_Description:
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- Entity_Type:
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- Entity_Type_Label: Band_1
- Attribute:
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- Attribute_Label: ObjectID
- Attribute_Definition: Internal feature number.
- Attribute_Definition_Source: ESRI
- Attribute_Domain_Values:
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- Unrepresentable_Domain:
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Sequential unique whole numbers that are automatically generated.
- Attribute:
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- Attribute_Label: Value
- Attribute:
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- Attribute_Label: Count
- Attribute:
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- Attribute_Label: Green
- Attribute:
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- Attribute_Label: Blue
- 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: VeeAnn A. Cross
- Contact_Organization: U.S. Geological Survey
- Contact_Position: Marine Geologist
- 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 x2251
- Contact_Facsimile_Telephone: (508) 457-2310
- Contact_Electronic_Mail_Address: vatnipp@usgs.gov
- Resource_Description: Downloadable Data
- Distribution_Liability:
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These data were prepared by an agency of the United States Government. Neither the United States government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof. Although all data published in this report have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials.
- Standard_Order_Process:
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- Digital_Form:
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- Digital_Transfer_Information:
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- Transfer_Size: 6.509
- Metadata_Reference_Information:
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- Metadata_Date: 20031006
- Metadata_Contact:
-
- Contact_Information:
-
- Contact_Person_Primary:
-
- 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 2.7.3 on Mon Oct 06 12:35:54 2003