Seasonal emanation of radon at Ghuttu, northwest Himalaya: Differentiation of atmospheric temperature and pressure influences.

Continuous monitoring of radon along with meteorological parameters has been carried out in a seismically active area of Garhwal region, northwest Himalaya, within the frame work of earthquake precursory research. Radon measurements are carried out by using a gamma ray detector installed in the air column at a depth of 10m in a 68m deep borehole. The analysis of long time series for 2006-2012 shows strong seasonal variability masked by diurnal and multi-day variations.

Radon variability in borehole from Multi-Parametric Geophysical Observatory of NW Himalaya in relation to meteorological parameters.

Radon has been measured continuously at an interval of 15 min at 10 m depth in a 68 m deep borehole. Five years of high resolution data of radon sampled at 15 min shows a complex trend with strong seasonal and diurnal trends. This temporal variation of radon has high emanation during summer and low concentration in winter.

Seasonal and daily variation of radon at 10 m depth in borehole, Garhwal Lesser Himalaya, India.

Mostly accepted and widely reported radon (Rn(222)) measurements, a tool for earthquake precursor research, is a part of multi-parametric geophysical observation in the Garhwal Lesser Himalaya for earthquake related studies. Radon is being recorded continuously at an interval of 15 min at 10 m depth in a 68 m deep borehole. Three years high resolution 15 min data at 10 m depth shows a complex trend and has a strong seasonal effect along with some diurnal, semi-diurnal and multi-day recurring trends.