Interpretation of the Sidescan-sonar Imagery in Lake Mohave

Metadata also available as - [Questions & Answers] - [Parseable text] - [XML]

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: David C. Twichell
Originator: David S. Foster
Publication_Date: 2005
Title: Interpretation of the Sidescan-sonar Imagery in Lake Mohave
Geospatial_Data_Presentation_Form: vector digital data
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2004-1247
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage: https://doi.org/10.3133/ofr20041247
Online_Linkage: https://pubs.usgs.gov/of/2004/1247/htmldocs/metadata.htm
Online_Linkage: Larger_Work_Citation:
Citation_Information:
Originator: VeeAnn A. Cross
Originator: David S. Foster
Originator: David C. Twichell
Publication_Date: 2005
Title: Lake Mohave Geophysical Survey 2002: GIS Data Release
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2004-1247
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: https://pubs.usgs.gov/of/2004/1247/
Description:
Abstract:
Lake Mohave is one of several multi-purpose reservoirs that have been constructed on the Colorado River. The lake was formed upon completion of the Davis Dam in 1953. No mapping of the floor of the lake had been conducted since completion of the Davis Dam. The U.S. Geological Survey, in cooperation with researchers from the University of Nevada Las Vegas, completed a geophysical survey of this lake in April 2002. The survey included collection of sidescan sonar imagery of nearly the entire lake floor, and high-resolution seismic-reflection profiles along widely spaced lines throughout the lake. The detailed mapping of the lake floor was used to determine the amount of sediment that had accumulated in the lake since impoundment, its distribution, and the processes of deposition.
Purpose:
This shapefile is intended to provide an interpretation of the sidescan-sonar imagery collected in Lake Mohave.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20020418
Ending_Date: 20020425
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -114.713653
East_Bounding_Coordinate: -114.570320
North_Bounding_Coordinate: 35.869129
South_Bounding_Coordinate: 35.200015
Keywords:
Theme:
Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:e6babb76-36b8-418d-b71a-5ea03300b1d2
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: bounds
Theme_Keyword: CMGP
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: geologic map
Theme_Keyword: geology
Theme_Keyword: lake
Theme_Keyword: OF 2004-1247
Theme_Keyword: Open-File Report
Theme_Keyword: polygon
Theme_Keyword: reservoir
Theme_Keyword: shapefile
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Woods Hole Science Center
Theme_Keyword: interpretation
Theme_Keyword: field activity identifier H-1-02-SW
Theme_Keyword: field activity serial number 02020
Theme:
Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: scientific interpretation
Theme_Keyword: geophysics
Theme_Keyword: geospatial datasets
Theme_Keyword: lakebed characteristics
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Arizona
Place_Keyword: Colorado River
Place_Keyword: Davis Dam
Place_Keyword: Hoover Dam
Place_Keyword: Lake Mohave
Place_Keyword: Las Vegas
Place_Keyword: Mojave Desert
Place_Keyword: Nelson's Landing
Place_Keyword: Nevada
Place_Keyword: North America
Place_Keyword: United States
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
Data_Quality_Information:
Logical_Consistency_Report: Information unavailable from original metadata.
Completeness_Report: Information unavailable from original metadata.
Lineage:
Process_Step:
Process_Description:
The completed sidescan-sonar mosaic in UTM, Zone 11, NAD83 projection was loaded into ArcView3.3.
Process_Date: unknown
Process_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
Process_Step:
Process_Description:
Based on variations in the backscatter of the sidescan-sonar imagery and information available from seismic-reflection profiles, polygons were drawn around interpreted features on the bottom of Lake Mohave.
Process_Date: unknown
Process_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
Process_Step:
Process_Description:
Using the calcapl.ave script contained in the ESRI samples directory, the AREA and PERIMETER were calculated for each polygon. These values are in units of meters, based on the UTM, Zone 11, NAD 83 projection.
Process_Date: unknown
Process_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
Process_Step:
Process_Description:
Edits to the metadata were made to fix any errors that MP v 2.9.36 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Attempted to modify http to https where appropriate. Modified the data citation to add series and publication information, as well as include a landing page link. Added the distribution format and link to the data in the standard order process section. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent.
Process_Date: 20171205
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
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
Process_Step:
Process_Description: USGS Thesaurus keywords added to the keyword section.
Process_Date: 20180720
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
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
Process_Step:
Process_Description: Crossref DOI link was added as the first link in the metadata.
Process_Date: 20191118
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
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
Process_Step:
Process_Description:
Added keywords section with USGS persistent identifier as theme keyword.
Process_Date: 20200908
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
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
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: G-polygon
Point_and_Vector_Object_Count: 584
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.00001
Longitude_Resolution: 0.00001
Geographic_Coordinate_Units: Decimal degrees
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
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: sscan_interp
Entity_Type_Definition: Information unavailable from original metadata.
Entity_Type_Definition_Source: Information unavailable from original metadata.
Attribute:
Attribute_Label: FID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain:
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: ID
Attribute_Definition:
Number automatically generated when each polygon feature was created.
Attribute_Definition_Source: Software generated.
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 0
Enumerated_Domain_Value_Definition: Information unavailable from original metadata.
Enumerated_Domain_Value_Definition_Source: Information unavailable from original metadata.
Attribute:
Attribute_Label: INTERP
Attribute_Definition:
Abbreviation indicating the interpretation of the sidescan-sonar imagery.
Attribute_Definition_Source: David C. Twichell
Attribute_Domain_Values:
Unrepresentable_Domain: character set
Attribute:
Attribute_Label: AREA
Attribute_Definition:
Area of the polygon, in square meters, based on the UTM, Zone11, NAD83 projection.
Attribute_Definition_Source: Software calculated.
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1033.386
Range_Domain_Maximum: 16677829.418
Attribute_Units_of_Measure: square meters
Attribute:
Attribute_Label: PERIMETER
Attribute_Definition:
Perimeter of the polygon, in meters, based on the UTM, Zone11, NAD83 projection.
Attribute_Definition_Source: Software calculated.
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 137.794
Range_Domain_Maximum: 45497.027
Attribute_Units_of_Measure: meters
Overview_Description:
Entity_and_Attribute_Overview:
What follows is a more detailed description of the INTERP field in the shapefile. In this study, in referring to sidescan-sonar data, high-backscatter is highly reflective data with pixel values towards white, or a value of 255. Low-backscatter indicated low pixel values towards black, or values of 0.
Alluvial: Pre-impoundment alluvial fan deposits. The interpretation is based both on the pre-impoundment topography and the sidescan-sonar imagery. The imagery commonly shows a fine network of channels on the fan surfaces.
rw_alluvial: reworked alluvial fan deposits. These deposits are found in the former Colorado River channel off of alluvial fans. Usually there is a scarp/bank that separates the alluvial fan from the alluvium that has been reworked by the former river. These appear to be pre-impoundment deposits.
overbank: pre-impoundment overbank deposits occupy low-lying flat areas to either side of the pre-impoundment Colorado River channel. These areas usually are low-backscatter on the sidescan imagery often with high-backscatter spots. The interpretation draws both on the sidescan imagery and the pre-dam topography. The topography shows that these low-lying areas often were populated with cottonwood trees. The white spots on the sidescan image may be drowned trees, and the low-backscatter nature of the return may be because the sediment is finger-grained.
dunes: sub-aerial sand dunes. These look much like sand waves except that the wavelength is longer and they are not located within the pre-impoundment Colorado River. Instead, they are found adjacent to the river bed in low-relief overbank areas.
mw: mass-wasting deposits. These show on the sidescan image as high-backscatter areas, which commonly have bright targets in them. Many of these deposits are found off the mouths of washes, and are thought to represent debris flow deposits associated with floods. Some, however, may just be small alluvial fan deposits. Other mass-wasting deposits are found along the base of rock cliffs. Which of these deposits post-date vs. predate the formation of Lake Mohave is unknown.
rock: high-backscatter areas that coincide with steep cliffs on the pre-impoundment topography. Some of these areas may be semi-consolidated sediment that has not collapsed due to river undercutting prior to flooding of the area or to water saturation subsequent to the filling of Lake Mohave.
low bs: low backscatter areas on the sidescan image that are not in the pre-impoundment Colorado River bed nor in areas identified as overbank. The origin of these areas is unknown.
moderate: moderate backscatter areas on the sidescan image occur outside the pre-impoundment river bed and do not have the small channels that are characteristic of alluvial fan areas. In general they appear to be smooth sandy slopes to either side of the river.
bank: steep slope that shows as either high- or low-backscatter on the sidescan image. Their location, in general, aligns with the edge of the pre-impoundment Colorado River shown on the pre-dam topographic map. In general, the banks are found off overbank and alluvial fan areas where there is unconsolidated sediment that had been eroded by the river. By contrast, where rock cliffs fringe the original river, there are no bank features.
sw: sand waves with wavelengths of 10-30 m. They are only found on the floor of the pre-impoundment channel of the Colorado River, and are interpreted to be fluvially generated bedforms that have been inactive since filling of the reservoir. Sand waves mostly occur in areas of moderate backscatter.
sw_large: sand waves with wavelengths of 100-450 m. They are only found on the floor of the pre-impoundment channel of the Colorado River, and are interpreted to be fluvially generated bedforms that have been inactive since filling of the reservoir. Sand waves mostly occur in areas of moderate backscatter.
channel high: high backscatter on the channel floor includes areas with sidescan values between 180-254. In some places the backscatter is uniformly high and smooth and probably represents gravel beds. In other high backscatter places the return is more textured and may represent areas of outcrop or widely spread cobbles or boulders.
channel moderate: moderate backscatter on the channel floor includes areas with sidescan intensity values of 51-179. The backscatter mostly is uniform, and is interpreted to represent sand.
channel low: low backscatter on the channel floor includes areas with sidescan intensity values of 1-50. These areas usually occur along the edges of the channel often downstream of promontories. These areas are interpreted to represent mud deposits.
Entity_and_Attribute_Detail_Citation: U.S. Geological Survey
Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: David S. Foster
Contact_Organization: U.S. Geological Survey
Contact_Position: 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 x2271
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: dfoster@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 publication 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:
Format_Name: Shapefile
Format_Information_Content: A zip file contains the shapefile components.
Transfer_Size: 0.550
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Fees: none
Metadata_Reference_Information:
Metadata_Date: 20240318
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: whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240318)
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr2004-1247/sscan_interpmeta.html>
Generated by mp version 2.9.51 on Mon Mar 25 16:05:22 2024