Gulf of Mexico Region NAD27 Official Protraction Diagrams and Lease Maps Images

Description

Within the Gulf of Mexico, there are two types of maps that depict blocks that could be leased. An older format, known as the Leasing Map, was based on Texas or Louisiana State Plane mapping projections. Leasing Maps were created as oil/gas leasing expanded offshore of Texas and Louisiana. Eventually the Leasing Maps were projected so far offshore that negative coordinates were required to support the projection. This has created a wide variety of Leasing Maps in projection, shape and overall size, but the blocks remained consistent, and are never larger than the 5760 acres. Because the Leasing Maps reflect so many active leases, they are still being maintained. However, in areas further offshore where Leasing Maps have never been generated, the Official Protraction Diagram (OPD) is used. A standard OPD is 1 degree in latitude by 2 degrees in longitude (at lower latitudes: 0 - 48 degrees) as in the Gulf of Mexico. At higher latitudes (48 - 75 degrees) such as Alaska and northern Washington, OPDs are 3 degrees wide. OPD limits usually approximate the standard 1:250,000 scale U.S. Geological Survey topographic map series. The OPDs are numbered using the United Nations International Map of the World Numbering System. OPD names usually coincide with standard topographic sheet names when diagrams include land areas. OPD sheet names relate to land features, or to hydrographic features contained within the limits of the diagram. Shoreline planimetric detail is shown when it falls within the limits of a diagram. Older OPDs were prepared on mylar with manual cartographic methods and then scanned into Adobe .pdf files. Newer OPDs were prepared electronically and converted to Adobe .pdf files. Further information on the historic development of OPD's can be found in OCS Report MMS 99-0006: Boundary Development on the Outer Continental Shelf: https://www.boem.gov/uploadedFiles/BOEM/Oil_and_Gas_Energy_Program/Mapping_and_Data/99-0006.pdf Also see the metadata for each of the individual GIS files used to create these OPDs. The Official Protraction Diagrams (OPDs) and Supplemental Official Block Diagrams (SOBDs), serve as the legal definition for BOEM offshore boundary coordinates and area descriptions.

Resources

Name Format Description Link
0 https://www.boem.gov/Official-Protraction-Diagrams/

Tags

  • cadastre-theme
  • national-geospatial-data-asset
  • mississippi
  • pi
  • public-information
  • united-states
  • ngda
  • texas
  • tims-pi-dump
  • florida
  • louisiana
  • alabama

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