OCS Gulf NAD27 Block Polygons - 2nd Division

Outer Continental Shelf (OCS) blocks serve as the legal definition for BOEM offshore boundary coordinates used to define small geographic areas within an Official Protraction Diagram (OPD) or Leasing Map (LM) for leasing and administrative purposes. These polygons are clipped to the Submerged Land Act Boundary and Continental Shelf Boundaries. Only the most recently published paper or PDF versions of the OPDs, LMs or Supplemental Official Block Diagrams (SOBDs) should be used for official or legal purpose. These data were created in the applicable NAD83 UTM or NAD27 UTM/SPCS Projection and re-projected to GCS WGS84 (EPSG 4326) for management in BOEM's enterprise GIS. Because GIS projection and topology functions can change or generalize coordinates, these data are NOT an OFFICIAL record for the exact boundaries. These data are to be used for Cartographic purposes only and should not be used to calculate area.外大陆架（Outer Continental Shelf，OCS）区块作为美国海洋能源管理局（Bureau of Ocean Energy Management，BOEM）离岸边界坐标的法定界定标准，用于在官方标绘图（Official Protraction Diagram，OPD）或租赁地图（Leasing Map，LM）中划定小型地理区域，服务于租赁及行政管理工作。这些多边形要素已被裁剪至《淹没土地法》边界与大陆架边界范围之内。官方或法定用途仅可使用最新发布的OPD、LM或补充官方区块图（Supplemental Official Block Diagrams，SOBDs）的纸质版或PDF版本。本数据集初始采用适配的北美大地基准84通用横轴墨卡托（NAD83 UTM）或北美大地基准27通用横轴墨卡托/州平面坐标系统（NAD27 UTM/SPCS）投影，并被重新投影至世界大地测量系统1984地理坐标系统（EPSG 4326），以适配BOEM企业地理信息系统的管理需求。由于地理信息系统的投影与拓扑功能可能会对坐标进行变更或简化处理，本数据集并非精确边界的法定官方备案文件。本数据集仅可用于制图用途，不得用于面积计算。