Aerial search by using a helicopter in the districts hit by Southern Hyogo Prefecture earthquake. Especially relation of active faults with γ ray intensity

Very large damages were brought about by Southern Hyogo Prefecture earthquake as plural faults acted. the exact definition of active fault is given. The author cooperated in the investigations of the state of the disaster and active faults by using a helicopter, and took part in the discussion on hidden faults. The exploration of spatial γ ray was strongly demanded to help the elucidation of the Southern Hyogo Prefecture earthquake. Ace Helicopter Co. planned its own research and carried out the aerial search over the land and sea as wide as about 200 km2 in Awaji-Akashi district which became the center of the earthquake. In this aerial search, for the purpose of clarifying the continuity of confirmed active faults and the distribution of unconfirmed faults and crushed rock zones, the data were acquired by mounting the instrument for the simultaneous measurement of the intensity of aerial γ radiation and aerial magnetism on a helicopter. The relation of faults and fissure zones with γ ray intensity, the instrument for aerial γ ray search and the aerial exploration and its results are reported. (K.I.)