CHANGES IN GAS AND ISOTOPIC COMPOSITION OF GROUNDWATER DURING THE PREPARATION OF SEISMIC EVENTS (BY THE EXAMPLE OF TASHKENT GEODYNAMIC TEST SITE) 

Sh. S. Yusupov¹ , M. M. Zakirov^2,*, R. K. Umurzakov² , and L. Yu. Shin² 

¹ Mavlyanov Institute of Seismology, Uzbekistan Academy of Sciences,
ul. Zul’fiyakhanum, 3, Tashkent, 100128 Uzbekistan
² Karimov Tashkent State Technological University, Universitetskaya
ul., 3, Tashkent, 100128 Uzbekistan
*E-mail: mzakirov1957@mail.ru 

The article deals with the results of regime observations over changes in gas and isotope composition of groundwater in deep wells at the Tashkent geodynamic test plot. The results obtained and the revealed geochemical and isotopic anomalies responsible for the periods of preparation and completion of the 11.12.1980 Nazarbek earthquake are discussed. The analysis of the Nazarbek, Tuyabuguz (25.05.2013, M = 5.5, R = 50 km) and Marzhanbulak (26.05.2013, M = 6.2, R = 200 km) earthquakes has been performed. The main geochemical and isotopic anomalies responsible for the periods of preparation and occurrence of earthquakes are identified.

Key words: isotope, helium concentration, migration, molecular hydrogen, deuterium, groundwater, precursor, anomaly, variation, carbonates, thermobaric, fractionation

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