Isopach Map of Postimpoundment Sediment in Lake Mead - UTM Projection

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Metadata:
Identification_Information:
Citation:
Citation_Information:
Originator: David C. Twichell
Originator: VeeAnn A. Cross
Publication_Date: 2003
Title:
Isopach Map of Postimpoundment Sediment in Lake Mead - UTM Projection
Geospatial_Data_Presentation_Form: raster digital data
Online_Linkage:
Larger_Work_Citation:
Citation_Information:
Originator: David C. Twichell
Originator: VeeAnn A. Cross
Originator: Stephen D. Belew
Publication_Date: 2003
Title:
Mapping the floor of Lake Mead (Nevada and Arizona): Preliminary discussion and GIS data release
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 03-320
Publication_Information:
Publication_Place: Woods Hole Field Center, Woods Hole, MA
Publisher: U.S. Geological Survey
Online_Linkage:
Description:
Abstract:
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:
This GIS (ESRI) grid represents the integration of three datasets collected in 1999-2001 and represents the sediment thickness in Lake Mead as mapped with seismic-reflection equipment.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19990514
Ending_Date: 20010426
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -114.888307
East_Bounding_Coordinate: -114.006701
North_Bounding_Coordinate: 36.503170
South_Bounding_Coordinate: 35.994301
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: ArcView
Theme_Keyword: CMGP
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: grid
Theme_Keyword: isopach
Theme_Keyword: OFR03-320
Theme_Keyword: Open-File report
Theme_Keyword: sediment
Theme_Keyword: sediment thickness
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Woods Hole Field Center
Place:
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: Mojave 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:
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:
Contact_Information:
Contact_Person_Primary:
Contact_Person: David C. Twichell
Contact_Organization: U.S. Geological Survey
Contact_Position: Oceanographer
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 x2266
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: dtwichell@usgs.gov
Native_Data_Set_Environment:
Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4; ESRI ArcCatalog 8.2.0.700
Cross_Reference:
Citation_Information:
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:
Synthetic organic compounds and carp endrocrinology and histology, Las Vegas Wash and Las Vegas and Callville bays of Lake Mead Nevada
Series_Information:
Series_Name: Water-Resources Investigations
Issue_Identification: 96-4266
Publication_Information:
Publisher: U.S. Geological Survey
Cross_Reference:
Citation_Information:
Originator: H.E. Bevans
Originator: M.S. Lico
Originator: S.J. Lawrence
Publication_Date: 1998
Title:
Water quality in the Las Vegas Valley area and the Carson and Truckee River basins, Nevada and California, 1992-1996
Series_Information:
Series_Name: Circular
Issue_Identification: 1170
Publication_Information:
Publisher: U.S. Geological Survey
Cross_Reference:
Citation_Information:
Originator: K.J. Couvay
Originator: T.J. Leiker
Publication_Date: 1998
Title:
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:
Series_Name: Open-File Report
Issue_Identification: 98-633
Publication_Information:
Publisher: U.S. Geological Survey
Cross_Reference:
Citation_Information:
Originator: H.R. Gould
Publication_Date: 1951
Title: Some quantitative aspects of Lake Mead turbidity currents
Series_Information:
Series_Name: SEPM Special Publication
Issue_Identification: No. 2
Publication_Information:
Publisher: Society of Economic Paleontologists and Mineralogists
Cross_Reference:
Citation_Information:
Originator: J.F. LaBounty
Originator: M.J. Horn
Publication_Date: 1997
Title:
The influence of drainage from the Las Vegas Valley on the limnology of Boulder Basin, Lake Mead, Arizona-Nevada
Series_Information:
Series_Name: Journal of Lake and Reservoir Management
Issue_Identification: v. 13
Cross_Reference:
Citation_Information:
Originator: L.J. Paulson
Publication_Date: 1981
Title:
Nutrient management with hydroelectric dams on the Colorado River
Series_Information:
Series_Name: Technical Report
Issue_Identification: #8
Publication_Information:
Publication_Place:
Department of Biological Sciences, University of Nevada, Las Vegas, Nevada
Publisher: Lake Mead Limnological Research Center
Cross_Reference:
Citation_Information:
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:
Series_Name: Water Resources Data Nevada
Issue_Identification: NV-98-1
Publication_Information:
Publisher: U.S. Geological Survey
Data_Quality_Information:
Logical_Consistency_Report:
This isopach map represents the integration of three years of data collection. This time frame of data collection can introduce small discrepancies in the sediment thickness.
Completeness_Report: This dataset is complete for the time period it covers.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The navigation system used was a P-Code GPS system. Navigation was interpolated over as much as a 10 second interval, converted to UTM zone 11 coordinates and rounded to the nearest meter.
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: 10-20m
Horizontal_Positional_Accuracy_Explanation: Nominal accuracy for the system and including rounding errors.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
The nominal resolution of the chirp subbottom system is assumed to be 0.5 meters. Another uncertainty is the speed of sound in sediment, which for this study is assumed to be 1500 m/sec. Due to the generally thin nature of the sediment cover, inaccuracies in the speed of sound are not thought to have a high impact.
Quantitative_Vertical_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy_Value: 0.5 meters
Vertical_Positional_Accuracy_Explanation: acquisition system resolution
Lineage:
Process_Step:
Process_Description:
Seismic-reflecition profiles were interpreted in Landmark seismic interpretation software. The interpreted surfaces included the pre- and post-impoundment surfaces.
Process_Step:
Process_Description:
A supplemental horizon was created within Landmark which is the difference between the pre-and post-impoundment surfaces.
Process_Step:
Process_Description:
This thickness horizon was then exported from Landmark as X,Y,Z values in ASCII format.
Process_Step:
Process_Description:
This ASCII X,Y,Z file was then imported into Earthvision software package. Within Earthvision, these discrete points were gridded using the default spline gridding technique of earthvision.
Process_Step:
Process_Description:
The Earthvision grid was then exported as an X,Y,Z ASCII text file.
Process_Step:
Process_Description:
The Earthvision ASCII text file was then reformatted using an AWK script into an ESRI ASCII grid format.
Process_Step:
Process_Description:
The ESRI ASCII grid format was imported into ArcView and converted to the standard ESRI grid format.
Process_Step:
Process_Description: This grid was then clipped to the sediment limit shapefile.
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell
Row_Count: 2178
Column_Count: 3114
Vertical_Count: 1
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:
UTM_Zone_Number: 11
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -117.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 25.000000
Ordinate_Resolution: 25.000000
Planar_Distance_Units: meters
Geodetic_Model:
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
Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: David C. Twichell
Contact_Organization: U.S. Geological Survey
Contact_Position: Oceanographer
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 x2266
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: dtwichell@usgs.gov
Resource_Description: Downloadable Data
Distribution_Liability:
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:
Digital_Form:
Digital_Transfer_Information:
Transfer_Size: 27.761
Metadata_Reference_Information:
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:
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 12:10:07 2003