Bathymetric Position Index (BPI) Structures 10 m grid derived from gridded bathymetry of Alamagan Island, Commonwealth of the Northern Mariana Islands (CNMI), USA.

BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (10 m cell size) multibeam bathymetry, collected aboard NOAA Ship Hi'ialakai and R/V AHI, and it was created using the Benthic Terrain Modeler (https://coast.noaa.gov/digitalcoast/tools/btm.html). Cell values represent one of 14 classes in an index of seafloor terrains. This data set is for the shelf and slope environments of Alamagan Island. As part of the northern islands of the Mariana Islands archipelago, Alamagan's offshore terrain has a shelf (above -60m), and a deep shelf (below -60m), with escarpments that lead outside of the coverage area. Conversely, the southern islands each have a shelf (above -100m) with escarpments that lead to broad flat areas without forming a deeper shelf.