1. According to the data of magnetotelluric soundings and laboratory studies of physical properties of low crust and upper mantle xenoliths of the Southern Tien Shan, the position of Moho surface has been reconstructed to early Paleogene. 

The results of interpretation of magnetotelluric soundings, laboratory measurements of electroconductivity under high temperatures and pressure, measurements of elastic waves’ velocities and thermobarometry of low crust and upper mantle xenoliths have shown that the depth of occurrence of Moho boundary in the southern part of the Tien Shan has increased from 35 to 55 km during 70 million years. The value of heat flow at the surface during the same period of time has decreased from 80 mW/m² to 60 mW/m² indicating the cooling of the region’s lithosphere during this period of time.

 

2. We have received the explosion time-travel curves plotted on first arrivals of P and S waves at a distance of up to 230 km from a powerful industrial explosion (2.8 kT) near Toktogul Reservoir on the 22^nd of December, 2009. 

As a result of seismic studies came the explosion time-travel curves plotted on first arrivals of P and S waves at a distance of up to 230 km which are of great deficit in the world. The previous travel-time curve received as far back as in 1975 on the base of industrial explosion during creation of a power dam of Toktogul hydrostation contained considerable inaccuracies due to application of analogue equipment, synchronization by signals of broadcasting stations, operator reactions.  The travel-time curves received by using new digital seismic stations make it possible to calculate parameters of seismic events more accurately and can be used for studies of deep structure of the Earth’s crust. 

 

3. As a result of unipolar electromagnetic impacts in 2000-2005 for seismotectonic deformations, we have revealed that directions of contraction axes and the shearing mode have changed to a transpression for the western part of Bishkek proving ground.   

To study the influence of unipolar energy impacts (EI) on the mode of seismotectonic deformations (STD) we used the catalogue of focal mechanisms which contains the parameters of seismic focuses with К ≥ 6 within the KNET territory. We have formed 2 sampling groups of seismic events: the events occurred within 17 days before and after the EI. For the events occurred before the EI day for the western part of the investigated territory we have revealed the shearing nature of STD, and the transpression mode was revealed for the eastern part. And for the sampling group after the EI day, the shearing mode changes to tranpression mode in the western part of the proving ground. And here we note the changes in distribution of azimuths of contraction axes. Such changes in the state of geomedium can be caused by EI.

 

 4. We have determined the changes in intensity of geoacoustic emission (GAE) during operation of electrical prospecting generating plant (ERGU) for borehole observations around Bishkek geodynamic proving ground.  

The increase of GAE intensity (borehole № 1156, Gornaya Maevka) was recorded at all the measuring channels of geoacoustic equipment during operation of ERGU during measurements in August and September of 2010. The spectral analysis has shown that in some cases the dominant frequencies which had been unnoticeable before appear in spectrum immediately with the beginning of ERGU session while the old frequencies are preserved (among the new frequencies the ones higher than 200 Hz prevail). We can also observe the responses which appear in the broad frequency spectrum but with a clear dominance of frequencies higher than 200 Hz. There are some differences between spectra for different sensor components (intensity of new frequencies and time of their appearance from the beginning of ERGU session), however, frequency maximums are the same.