Options
Matcharashvili, T.
Loading...
Preferred name
Matcharashvili, T.
2 results
Now showing 1 - 2 of 2
- PublicationOpen AccessInfluence of strong electromagnetic discharges on the dynamics of earthquakes time distribution in the Bishkek test area (Central Asia)(2006-08)
; ; ; ; ;Chelidze, T.; Institute of Geophysics, Georgian Academy of Sciences, Tbilisi, Georgia ;De Rubeis, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Matcharashvili, T.; Institute of Geophysics, Georgian Academy of Sciences, Tbilisi, Georgia ;Tosi, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; ; ; From 08/01/1983 to 28/03/1990, at the Bishkek ElectroMagnetic (EM) test site (Northern Tien Shan and Chu Valley area, Central Asia), strong currents, up to 2.5 kA, were released at a 4.5 km long electrical (grounded) dipole. This area is seismically active and a catalogue with about 14100 events from 1975 to 1996 has been analyzed. The seismic catalogue was divided into three parts: 1975-1983 first part with no EM experiments, 1983-1990 second part during EM experiments and 1988-1996 after experiments part. Qualitative and quantitative time series non- linear analysis was applied to waiting times of earthquakes to the above three sub catalogue periods. The qualitative approach includes visual inspection of reconstructed phase space, Iterated Function Systems (IFS) and Recurrence Quantification Analysis (RQA). The quantitative approach followed correlation integral calculation of reconstructed phase space of waiting time distribution, with noise reduction and surrogate testing methods. Moreover the Lempel- Ziv algorithmic complexity measure (LZC) was calculated. General dynamics of earthquakes’ temporal distribution around the test area, reveals properties of low dimensional non linearity. Strong EM discharges lead to the increase in extent of regularity in earthquakes temporal distribution. After cessation of EM experiments the earthquakes’ temporal distribution becomes much more random than before experiments. To avoid non valid conclusions several tests were applied to our data set: differentiation of the time series was applied to check results not affected by non stationarity; the surrogate data approach was followed to reject the hypothesis that dynamics belongs to the colored noise type. Small earthquakes, below completeness threshold, were added to the analysis to check results robustness.243 366 - PublicationOpen AccessLaboratory study of electromagnetic initiation of slip(2002)
; ; ; ; ; ; ;Chelidze, T.; Institute of Geophysics,Georgian Academy of Sciences,Tbilisi,Georgia ;NoVaramashvili, N.; Institute of Geophysics,Georgian Academy of Sciences,Tbilisi,Georgia ;Devidze, M.; Institute of Geophysics,Georgian Academy of Sciences,Tbilisi,Georgia ;Tchelidze, Z.; Institute of Geophysics,Georgian Academy of Sciences,Tbilisi,Georgia ;Chikhladze, V.; Institute of Geophysics,Georgian Academy of Sciences,Tbilisi,Georgia ;Matcharashvili, T.; Institute of Geophysics,Georgian Academy of Sciences,Tbilisi,Georgia; ; ; ; ; Recently Russian seismologists reported the triggering effect of MHD soundings on microseismic activity in the Central Asia test area.The paper focuses on an experimental test of the possibility of triggering the mechanical instability of a system that is close to critical state by a series of electromagnetic pulses.The mechanical system consisted of two pieces of rock;the upper piece can slip on the fixed supporting sample if the latter one is tilted up to the critical angle.In this state,the triggering of mechanical instability by some weak impact such as electrical pulse became more probable.The slope of support in the experiment is an analogue of tectonic stress in natural conditions.The preliminary experiments,carried out in a dry environment,at the humidity of atmosphere 30-50%,show that a strong EM-pulse induces sliding of a sample of rock (granite,basalt,labradorite)placed on the supporting sample which is inclined at the slope close to,but less than,the critical angle with a probability 0.07.137 186