Gamma-Ray Spectrometry in Radioactive Prospecting: Application Tool as Detecting Fault Trace

Abstract

In order to clarify the possibility of fault detection by gamma-ray spectrometry (GRS), radioactivity prospecting including soil radon gas survey, etc., was carried out on already-known faults of four areas included active faults. As a result, it was shown that it is possible to detect fault traces with the following three indices: (1) the continuity of anomaly points with an increasing rate Bi/Tl above the threshold defined for each study area. (2) The continuity of peak points of non-diffusive radon. (3) The continuity of conversion points where the average value changes in the stepped fluctuation pattern of nuclide and nuclide ratio. The index of (1) was near all four faults within 0–30 m of the known fault location. All fault-related anomalies of the index (1) were formed by local maxima in Bi and local minima or decreasing trends of Tl. Therefore, it is difficult to detect faults using only total gamma ray measuring equipment such as survey meters, which has been done so far. In order to continue to develop analysis technology for GRS, in addition to accurate GRS measurements, it is also necessary to develop analysis technology using Artificial Intelligence (AI) technology, etc.