HTML Containing Interpreted and Uninterpreted JPEG Images of Seismic-Reflection Profiles Collected in Lake Mead in 2000

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: VeeAnn A. Cross
Originator: David C. Twichell
Publication_Date: 2003
Title:
HTML Containing Interpreted and Uninterpreted JPEG Images of Seismic-Reflection Profiles Collected in Lake Mead in 2000
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
Edition: 1.0
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
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:
These images of the seismic-reflection profiles are provided so that individuals can preview the seismic data without the requirement of special software.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20000601
Ending_Date: 20000606
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -114.876820
East_Bounding_Coordinate: -114.737250
North_Bounding_Coordinate: 36.135920
South_Bounding_Coordinate: 36.081650
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: seismic
Theme_Keyword: JPEG
Theme_Keyword: chirp
Theme_Keyword: images
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: CMGP
Theme_Keyword: Woods Hole Field Center
Theme_Keyword: Open-File Report
Theme_Keyword: OFR03-320
Place:
Place_Keyword_Thesaurus: General
Place_Keyword: Lake Mead
Place_Keyword: Nevada
Place_Keyword: United States
Place_Keyword: Las Vegas
Place_Keyword: Hoover Dam
Place_Keyword: Colorado River
Place_Keyword: Mojave Desert
Place_Keyword: Las Vegas Wash
Place_Keyword: Las Vegas Bay
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: 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
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: V.A. Cross
Originator: D.C. Twichell
Publication_Date: 2003
Title:
Archive of Seismic-Reflection Data Collected During USGS Cruise Lake Mead 00027 in Lake Mead - Nevada, 1-6 June, 2000
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 03-004
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:
Completeness_Report:
These files represent images of all the seismic-reflection data collected in Lake Mead in 2000 by the USGS.
Lineage:
Process_Step:
Process_Description:
The seismic data collected in 2000 was Knudsen chirp seismic data. These data needed several corrections applied in the post-processing phase.
Process_Step:
Process_Description:
The seismic processing software package SIOSEIS was used to convert the Knudsen segy data to "true" chirp seismic data, while at the same time removing an artificial 5 ms delay for each trace, renumber the traces so that each seismic data file started at shot 1 and incremented each shot by 1.
Process_Step:
Process_Description:
These corrected SEG-Y data were then loaded into Landmark software and interpreted.
Process_Step:
Process_Description:
CGM images were created of each seismic profile - with the interpretation and without the interpretation. Therefore 2 images for each profile. The interpreted post-impoundment surface is the blue line, while the interpreted pre-impoundment surface is the red line.
Process_Step:
Process_Description: These CGM images were converted to JPEGs using Larson software.
Process_Step:
Process_Description:
These jpegs were then downsampled to a GIF format using djpeg on a UNIX system.
Process_Step:
Process_Description:
These GIFS were then converted back to JPEGs using the convert command on a UNIX system.
Process_Step:
Process_Description:
An html document was generated within Dreamweaver for each seismic line to hold both the interpreted and uninterpreted seismic-reflection profiles.

Spatial_Data_Organization_Information:

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geodetic_Model:

Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
These images are intended only as previews of the seismic-reflection data. In each image, the x-axis represents shot point, the y-axis is two-way travel time in milliseconds. The scale bar along the bottom of the image is inaccurate due to a bug in the digital processing software and therefore should be ignored.

Distribution_Information:
Distributor:
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
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.

Metadata_Reference_Information:
Metadata_Date: 20030123
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_Access_Constraints: none
Metadata_Use_Constraints: none
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Generated by mp version 2.7.23 on Mon Oct 06 12:47:12 2003