Tonsina Geophysical Survey

The Tonsina electromagnetic and magnetic airborne geophysical survey data were acquired with a DIGHEMv Electromagnetic (EM) system and a CGG D1344 cesium magnetometer with a Scintrex CS3 cesium sensor. The EM and magnetic sensors were flown at a height of 30 meters (m). In addition the survey recorded data from radar and laser altimeters, GPS navigation system, 50/60 Hz monitors and video camera. Flights were performed with an AS-350-B3 Squirrel helicopter at a mean terrain clearance of 60 m along NW-SE (345 degrees) survey flight lines with a spacing of 400 m. Tie lines were flown perpendicular to the flight lines at intervals of approximately 4,800 m. These data were produced under contract between the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (DGGS), and CGG Land (U.S.) Inc. Airborne geophysical data for the area were acquired and processed by CGG in 2014 and 2015. The project was funded by the Alaska State Legislature as part of the Alaska Airborne Geophysical and Geological Mineral Inventory Program and the Alaska Strategic and Critical Minerals Assessment Capital Improvement Project.

Publications

• GPR 2015-1. Tonsina electromagnetic and magnetic airborne geophysical survey data compilation.