A brief description on radon monitoring in India in some seismically sensitive areas

Radon anomalies in both groundwater as well as soil gas prior to a major earthquake were first observed in the Tashkent region (1966) of USSR. Since then, scientists have taken note of geochemical changes in seismically active areas on a regular basis. Emanation of radon gases and associated anomalies in spring and well waters have been observed in various seismically active regions in the Himalayan belt — both in the north-eastern as well as in the western part of the mountain chain. An attempt has been made in this paper to give a brief review of the radon monitoring work done in the Indian subcontinent in some seismically active regions