Gamma Isotope Mapping System

The CAIS-designed Gamma Isotope Mapping System (GIMS) enables the rapid collection of surficial sediment data in any type of aquatic environment, providing:  

  • Rapid radionuclide and bathymetric survey over a broad geographic area;
  • Real time monitoring of natural or anthropogenic gamma activity in surficial sediments;
  • Near real time mapping of gamma activity in surficial sediments.


The GIMS has a variety of proven applications, including assessment of offshore mineral resources, monitoring of offshore dredged sediment disposal sites, establishment of baseline conditions in environmentally sensitive areas.

The system is comprised of a gamma radiation detector mounted aboard a towed platform to determine sediment surface gamma activities of 214Bi, 208Tl, and 40K, all "pathfinder" elements that are indicative of the nature of sediments. These activities can be used to interpret and map the types of surficial sediments present. With minor system adjustments, anthropogenic isotopes such as 137Cs can also be readily monitored.

The system can be deployed in water depths of up to 100 meters and towed at speeds of 2 to 3 knots along survey transects. Two- and three-dimensional bathymetric and isotopic maps are generated in near real time during the survey process.


Selected Images   Publications


The GIMS is available on a contract basis.

For further information contact Dr. Scott E. Noakes (706) 542-6134