Anomalous soil radon fluctuations – signal of earthquakes in Nepal and eastern India regions

The present paper deals with pre-seismic soil radon-222 recorded at two different locations 200 m apart, at Jadavpur University main campus, Kolkata, India. Solid state nuclear track detector method is used for detection of the radioactive radon gas. Two simultaneous 4-month long time series data have been analysed. Anomalous fluctuations in the radon datasets have been observed prior to recent earthquakes in Nepal and eastern India during the monitoring period, mainly, the massive 25th April 7.8 M Nepal earthquake. The simultaneous measurements assist in identifying seismogenic radon precursor efficiently.