Type Enterprise Geodatabase Feature Class
Aliquots and other cadastre information the BOEM produces are generated in accordance with 30 Code of Federal Regulations (CFR) Part 556.8 Subpart A, (formerly Part 256.8 Subpart A (2010)) to support Federal land ownership and mineral resource management.
Aliquots are generated from Outer Continental Shelf (OCS) blocks by subdividing each block into 16ths, and this further subdivision allows for more detailed boundary delineation in offshore energy leasing. The aliquots use a letter designation in addition to their parent protraction number and OCS block number (e.g., NK18-02, 6822F). A full OCS block is 4800 x 4800 meters, while an aliquot measures 1200 x 1200 meters. Smaller, clipped aliquots are found along the Federal/State OCS boundary and along UTM zone borders. Only the most recently published paper or PDF versions of the Official Protraction Aliquot Diagram (OPAD) should be used for official or legal purposes. The OPAD maps can be accessed by clicking on the link in the Official Protraction Aliquot Diagram field of the attribute table.
Bureau of Ocean Energy Management (BOEM), Office of Strategic Resources, Geospatial Services Division
This data was created in the applicable NAD83 UTM Projection and re-projected to WGS84 Geographic. Because GIS projection and topology functions can change or generalize coordinates, these GIS files are NOT an OFFICIAL record for the exact boundaries. These files are to be used for Cartographic purposes only. This data should not be used to calculate area.
| West | -98.049058 | East | -87.976228 |
| North | 29.982088 | South | 24.925110 |
| Maximum (zoomed in) | 1:5,000 |
| Minimum (zoomed out) | 1:150,000,000 |
Bureau of Ocean Energy Management (BOEM), Office of Strategic Resources, Geospatial Services Division
National Dataset covering Gulf of Mexico and U.S. Territories and Possessions.
This data was created in the applicable NAD83 UTM Projection and re-projected to WGS84 Geographic. Because GIS projection and topology functions can change or generalize coordinates, these GIS files are NOT an OFFICIAL record for the exact boundaries. These files are to be used for Cartographic purposes only. This data should not be used to calculate area.
This national dataset was created using data from BDS. The data is stored in the applicable NAD83 (Atlantic, Alaska, Gulf of Mexico and Pacific Coast, Puerto Rico, and U.S. Virgin Islands) and WGS84 (Pacific Territories) and appended to the WGS84 Geographic national geodatabase to display as the Aliquots – Third Division national dataset. The BDS Frontier Tool was used to generate the Aliquots for the Gulf of Mexico areas only and displayed on published Official Protraction Aliquot Diagrams. Aliquot datasets created using TIMS data is not incorporated. This April 28, 2023, dataset is used for viewing only in the OMC Navigator application and is not currently available for download.
Aliquot 16
BOEM Boundary Delineation System
Internal feature number.
Esri
Sequential unique whole numbers that are automatically generated.
Feature geometry.
Esri
Coordinates defining the features.
The indicator used to identify the location of the 1/64 aliquot within the block. The block is subdivided into 1/64 aliquots using the Public Land Survey System (PLSS) for describing the 1/64 aliquot’s location on the grid.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The indicator used to identify the Bureau of Ocean Energy Management (BOEM) Outer Continental Shelf (OCS) Region.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The total surface area within an OCS aliquot. This includes all state, unencumbered federal and/or encumbered federal portions, such as deferred, disputed, Section 8(g), and/or withdrawn parcels. It is measured in acres or hectares as appropriate. The total area in an aliquot does not exceed 355.83 acres or 144 hectares.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
An alpha-numeric foreign key for identifying the OCS block that the aliquot resides within. The BLOCK AREA BLOCK IDENTIFIER for each aliquot will match the BLK_ID (Primary Key) of the block in which the aliquot resides.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The identifier of the subdivision of an Official Protraction Diagram or Leasing Map that the block corner point falls within.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The username of the database editor who initially created the data record.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The indicator of the classification of OCS aliquot. This code is used to flag aliquots for generation of Supplemental Official OCS Aliquot Diagrams (split aliquot diagrams).
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
Index Diagram link
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
OPD link
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
OPAD link
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The day, month, and year the data record was first created in the database.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The day, month, year the block is associated to the Official Protraction Diagram or Leasing Map it falls within and is uploaded to the database.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The month, day, and year of the OCS Block that the boundary line resides within.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The day, month, and year the data record was last edited in the database.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The indicator used to identify the appropriate unit of areal measurement for the OPD or Leasing Map. All Leasing Maps in the State Plane Coordinate System have areas measured in acres. All OPDs in the UTM coordinate system have areas measured in hectares.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The username of the database editor who last edited the data record.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
An alpha-numeric foreign key for identifying the OCS protraction that the aliquot resides within. The PROT_ID for each aliquot will match the PROT_ID (Primary Key) of the protraction in which the aliquot resides.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The name of the Official Protraction Diagram or Leasing Map that the aliquot falls within.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
Concatenated block and aliquot label used for maps.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
Uppercase aliquot label used for maps.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
A unique, alpha-numeric identifier (Primary Key) for identifying the OCS aliquot subdivision of a block.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
An indicator of the status of the record (active or historical).
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The identifier of the Official Protraction Diagram or Leasing Map that the aliquot falls within.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
An explanation or description associated with individual aliquot records.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
Used for describing the maximum extent of an aliquot (as displayed on the SOAD). This value is the larger of the two X-coordinate values of the grid lines along the X-axes of an aliquot.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
Used for describing the maximum extent of an aliquot (as displayed on the SOAD). This value is the larger of the two Y-coordinate values of the grid lines along the Y-axes of an aliquot.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
Used for describing the minimum extent of an aliquot (as displayed on the SOAD). This value is the smaller of the two X-coordinate values of the grid lines along the X-axes of an aliquot.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
Used for describing the minimum extent of an aliquot (as displayed on the SOAD). This value is the smaller of the two Y-coordinate values of the grid lines along the Y-axes of an aliquot.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The x-coordinate of the centroid of the OCS aliquot.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The y-coordinate of the centroid of the OCS aliquot.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The latitude coordinate of the centroid of the OCS aliquot.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The longitude coordinate of the centroid of the OCS aliquot.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The measured distance between the aliquot’s southwestern corner point (COORD_SEQ_NUM=1) and southeastern corner point (COORD_SEQ_NUM=2) along the x-axis. It is measured in meters or US feet as appropriate.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The measured distance between the aliquot’s inner corner point and the aliquot’s zone edge point along the y axis. It is measured in meters or US feet as appropriate. The total distance for an aliquot y grid distance does not exceed 39.37 U.S. Survey Feet or 12 meters.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
A Universal Unique Identifier in which values are automatically assigned by the geodatabase when the data record is created. This ID is necessary for maintaining object uniqueness across replicas.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
The indicator used to identify the appropriate map template to utilize when generating the OPAD or SOAD.
BOEM Boundary Delineation System
Field in a feature class does not originate with any metadata authority.
Shape Area
Esri
Field in a feature class does not originate with any metadata authority.
Shape length
Esri
Field in a feature class does not originate with any metadata authority.