Airborne Radiometric Survey over Puerto Rico and the Surrounding Islands and Shelf, 2023-2024

Radiometric data collected as part of a high-resolution airborne magnetic and radiometric survey over Puerto Rico, the islands of Vieques and Culebra, and the surrounding shelf are provided here as flight line databases, grids, and imagery. The dataset was acquired as part of the USGS Earth Mapping Resource Initiative (Earth MRI) to improve our understanding of the fundamental geologic framework of the region with applications to evaluating natural resources and geologic hazards. Radiometric (or gamma-ray) surveys measure naturally occurring low-level gamma rays from the upper 0-0.5 m of the surface and use their energy spectra to estimate broad amounts of potassium, thorium, and uranium. The data were acquired and processed by Terraquest under contract to Dewberry and the USGS. Data collection took place over two time periods, from March 2023 to May 2023 and December 2024 to March 2025 using a fixed-wing airplane. A total of 70,031 linear kilometers of data were collected. Details regarding the flights and data processing are described in the contractor report provided on the landing page of this release.