A groundwater radon monitoring in the southern and western part of Sakhalin Island was carried out in 2014 in order to study the correlation between radon anomalies and the seismic activity of the region. The objects of investigations were located within large tectonic dislocations of the island—the southern part of the Central Sakhalin fault and the central part of the West Sakhalin fault. The soil gas monitoring was carried out using a Sirad probe (Quarta-Rad, Russia) and the continuous radon monitoring in the groundwater was carried out using a Radon Seismic Station (CPC-05, NTM-Zashita, Russia). The effect of geochemical parameters, namely, temperature, pressure and conductivity on the radon emission has been studied. The present work contains an analytical protocol which is based on the analysis of radon emitted from the fault planes, a geo- chemical precursor when predicting the tectonic activity.
 Einarsson, P., Theodórsson, P., Hjartardóttir, á.R. and Guejónsson, G.I. (2008) Radon Changes Associated with the Earthquake Sequence in June 2000 in the South Iceland Seismic Zone. Pure and Applied Geophysics, 165, 63-74. http://dx.doi.org/10.1007/s00024-007-0292-6
 Fleischer, R.L. (1981) Dislocation Model for Radon Response to Distant Earthquakes. Geophysical Research Letters, 8, 477-480. http://dx.doi.org/10.1029/GL008i005p00477
 Igarashi, G., Saeki, S., Takahata, N., Sumikawa, K., Tasaka, S., Sasaki, Y., Takahashi, M. and Sano, Y. (1995) Groundwater Radon Anomaly before the Kobe Earthquake in Japan. Science, 269, 60-61. http://dx.doi.org/10.1126/science.269.5220.60
 Kumar, A., Singh, S., Mahajan, S., Bajwa, B.S., Kalia, R. and Dhar, S. (2009) Earthquake Precursory Studies in Kangra Valley of North West Himalayas, India, with Special Emphasis on Radon Emission. Applied Radiation and Isotopes, 67, 1904-1911. http://dx.doi.org/10.1016/j.apradiso.2009.05.016
 Liu, K.K., Yui, T.F., Yeh, Y.H., Tsai, Y.B. and Teng, T.L. (1984/85) Variations of Radon Content in Groundwaters and Possible Correlation with Seismic Activities in North-ern Taiwan. Pure and Applied Geophysics, 122, 231-244.
 Mogro-Campero, A., Fleischer, R.L. and Likes, R.S. (1980) Changes in Subsurface Radon Concentration Associated with Earthquake. Journal of Geophysical Research, 85, 3053-3057. http://dx.doi.org/10.1029/JB085iB06p03053
 Talwani, P., Moore, W.S. and Chiang, J. (1980) Radon Anomalies and Microearthquakes at Lake Jocassee, South Carolina. Journal of Geophysical Research, 85, 3079-3088. http://dx.doi.org/10.1029/JB085iB06p03079
 Walia, V., Su, T.C., Fu, C.C. and Yang, T.F. (2005) Spatial Variations of Radon and Helium Concentrations in Soil-Gas across Shan-Chiao Fault, Northern Taiwan. Radiation Measurements, 40, 513-516. http://dx.doi.org/10.1016/j.radmeas.2005.04.011
 Walia, V., Virk, H.S. and Bajwa, B.S. (2006) Radon Precur-sory Signals for Some Earthquakes of Magnitude > 5 Occurred in N-W Himalaya: An Overview. Pure and Applied Geo-physics, 163, 711-721. http://dx.doi.org/10.1007/s00024-006-0044-z
 Al-Tamimi, M.H. and Abumurad, K.M. (2001) Radon Anomalies along Faults in North of Jordan. Radiation Measurements, 34, 397-400. http://dx.doi.org/10.1016/S1350-4487(01)00193-7
 Fu, C.C., Yang, T.F., Walia, V. and Chen, C.H. (2005) Reconnaissance of Soil Gas Composition over the Buried Fault and Fracture Zone in Southern Taiwan. Geochemical Journal, 39, 427-439. http://dx.doi.org/10.2343/geochemj.39.427
 Singh, S., Sharma, D.K., Dhar, S. and Randhawa, S.S. (2006) Geological Significance of Soil Gas Radon: A Case Study of Nurpur Area, District Kangra, Himachal Pradesh, India. Radiation Measurements, 41, 482-485. http://dx.doi.org/10.1016/j.radmeas.2005.10.009
 Scholz, C.H., Sykes, L.R. and Aggarwal, Y.P. (1973) Earthquake Prediction: A Physical Basis. Science, 181, 803-810. http://dx.doi.org/10.1126/science.181.4102.803