Detection system description
The marine sensor was developed for measuring in‐ situ the activity concentration of gamma‐ray emitters in the marine environment using medium resolution crystal and digital electonic units. It is characterized by: capability to offer free‐of‐error continuous functionality; pluggable watertight cabling system for real time data transmission in case of operation at a buoy; high efficiency due to the detection crystal and to the minimum gamma‐ray absorption in the enclosure material. Along with the sensor, a methodology has been developed (by using simulation codes and laboratory experiments) to convert the acquired gamma‐ray counts to quantitative activity concentrations (in absolute units Bq/L or Bq/m3), even for low level radioisotope concentrations. The combination of the state‐of‐the‐art in situ gamma‐ray underwater medium resolution sensor with the reliable quantification methodology renders GeoMAREA a gamma‐ray spectrometer which is capable of performing measurements for different applications in the marine environment.

The system has been designed for aquatic applications at depths up to 600 m. During its development phase it has been tested and deployed in the laboratory and in Mediterranean Sea for geophysical and radioecology studies. Intercalibration exercises have also been performed ensuring the reliability and the quality of the results using in-situ and lab results from the same environment.

GeoMAREA detection system has small dimensions (40 x 10 cm), allowing easily transportation worldwide. It is packed in typical suitcase along with all necessary auxiliary instrumentation (cables, specific application platform and housing of the battery pack) and it can be easily manipulated in the field.

Deployment Options
GeoMAREA can be installed on floating measuring systems (buoys) for continuous operation in the marine environment and the data can be either transmitted in real-time mode to any operational centre or can be saved in an internal memory. The detection system provided data every specific time lag (user adjusted) Alternatively, GeoMAREA operates autonomously supplied by underwater battery packs. Furthermore, GeoMAREA may provide count rates in sequential mode for speciifc energy wondow.

Applications areas

  • Policy and decision‐making
  • Radioprotection, especially in coastal zone where nuclear power and waste processing plants operate (continuous monitoring and early warning)
  • Pollution assessment and monitoring
  • Radioecology studies – including monitoring radioactivity levels at the sea bottom – in coastal areas with industrial activity (cement, fertilizer, oil, mineral/mining, desalination plants)
  • Energy resources
  • Monitoring of natural radioactivity for hydrocarbons exploration activities (gas hydrates included) in the marine environment
  • Meteorology
  • Rainwater quantification and estimation of cloud type
  • Geophysical research
  • Gas emanation/activity of submarine faults, volcanoes and cold seeps
  • Quality and quantity assessment of submarine groundwater discharges

Advanced Training
Advanced training courses can be organized concerning the utilization of GeoMAREA system (familiarization with system modules and functions, maintenance, technical aspects for real-time acquisition and autonomous deployments) and the analysis of the acquired spectra.