L. Bogomolov - Academia.edu (original) (raw)

Papers by L. Bogomolov

The results of detail comparison of the data of the in-situ borehole geoacoustic and electromagne... more The results of detail comparison of the data of the in-situ borehole geoacoustic and electromagnetic measurements and the experiments with the rock specimens are given there. Similarity of the results of in-situ measurements and the data of laboratory experiments of electromagnetic effect at rock specimens is shown. The synchronous borehole geoacoustic and electromagnetic measurements in the range of 30-1200 Hz, that have been carrying since 2003 year on the base of deep (2542 m) G-1 borehole in the suburbs of Petropavlovsk-Kamchatsky, have allowed to show up the effect of the natural electromagnetic emission modulating impact (EEMI) on the intension of geoacoustic emission (GAE) of rocks in their natural relations. It follows from the results of measurements at the G-1 point, in periods corresponding the calm seismic situation in the region, that the time series correlation score of GAE and EEMI is very high (fig.1). Fig.1. Example of the results of the combined geoacoustic and ele...

Journal of Nuclear Materials, 1989

High precision measurements of Hall RH(T) and Seebeck S(T) coefficients have been carried out for... more High precision measurements of Hall RH(T) and Seebeck S(T) coefficients have been carried out for the first time on single crystals of rare earth dodecaborides RB12 (R - Ho, Er, Tm, Lu) at temperatures 1.8 - 300K. Low temperature anomalies associated with antiferromagnetic phase transitions in HoB12, ErB12 and TmB12 compounds have been detected on the temperature dependencies of RH(T)

Acta Physica Polonica Series a

High precision measurements of magnetoresistance ∆ρ/ρ = f (T, H) and magnetization M (T, H) were ... more High precision measurements of magnetoresistance ∆ρ/ρ = f (T, H) and magnetization M (T, H) were carried out on single crystals of rare-earth dodecaboride ErB12 at temperatures in the interval 1.8-30 K in magnetic fields up to 70 kOe. The high accuracy of the experiments allowed us to perform numerical differentiation and analyze quantitatively the behavior of the derivative d(∆ρ/ρ)/dH = f (T, H) and of the magnetic susceptibility χ(T, H)= dM /dH in paramagnetic and magnetically ordered (antiferromagnetic, T N ≈ 6.7 K and T M ≈ 5.85 K) phases of ErB 12 . It was shown that negative magnetoresistance anomalies observed in present study in paramagnetic state of ErB 12 may be consistently interpreted in the framework of a simple relation between resistivity and magnetization -∆ρ/ρ ∼ M 2 .

Izvestiya, Physics of the Solid Earth, 2014

An effect of high-power electromagnetic pulses of magneto-hydrodynamic (MHD) generator on the sei... more An effect of high-power electromagnetic pulses of magneto-hydrodynamic (MHD) generator on the seismic regime over the Northern Tien Shan and Pamir regions has been studied. An increased level of seismic activity was observed within 3 to 6 days after the MHD generator firing runs. It was suggested that electromagnetic pulses result in discharge of energy accumulated by the Earth crust

Tectonophysics, 2007

On the base of the GPS-measured velocity field referring to the recent crust movements over sizab... more On the base of the GPS-measured velocity field referring to the recent crust movements over sizable terrestrial areas (Central Tien Shan), the strain rate tensor is evaluated as the tensor components are governed by space gradients of the velocity field. The areas of the extreme values of the strain rate tensor components are shown to coincide with the highest seismic activity areas. Also shown is the fact that, in the direction of the crust surface layer compression, the deep layer electric conductivity reaches its maximum. A simplest explanation of this phenomenon is proposed.

Izvestiya, Physics of the Solid Earth, 2008

Seismotectonic strains (STSs) are calculated on the basis of the catalog of focal mechanisms of e... more Seismotectonic strains (STSs) are calculated on the basis of the catalog of focal mechanisms of earthquakes including more than 5000 events compiled at the Institute of Seismology, National Academy of Sciences of the Kyrgyz Republic, in order to investigate deformation processes in the Tien Shan (38 ° -44 ° N, 68 ° -80 ° E). A modern approach to STS classification based on the identification of 11 deformation settings (including four main, two extreme, and five transitional settings) is applied for constructing STS maps. Areal distributions of the Lode-Nadai coefficient, vertical component, and angle of the stress-state type are obtained. The results of the calculations are verified by comparing them with STS calculations using focal mechanisms of 116 strong earthquakes from the centroid moment tensor catalog of Harvard University that occurred in the studied region in -2003 91.45.Bg

Izvestiya, Physics of the Solid Earth, 2010

... the sublatitudinal strike of ridges and troughs, the reverse faultthrust fault motion, and o... more ... the sublatitudinal strike of ridges and troughs, the reverse faultthrust fault motion, and other structural fea tures [Zubovich et al., 2007]. As is known, the Northern Tien Shan is an active fault region, continuously extend ing by more than 600 km along the margins of the oro gene. ...

Izvestiya, Physics of the Solid Earth, 2011

ABSTRACT The data of borehole geoacoustic and electromagnetic measurements in Kamchatka are compa... more ABSTRACT The data of borehole geoacoustic and electromagnetic measurements in Kamchatka are compared with the results of laboratory and field experiments on electromagnetic excitation of rocks. A noticeable similarity in the responses of the natural geological medium and rock specimens is observed. The field experiments with controlled electromagnetic sources show that the geophones placed in boreholes are capable of reliably detecting the responses of rocks in situ to electric impacts as low as 0.5 mV/m. The obtained results provide the experimental evidence in favor of the previously proposed hypothesis of modulation of geoacoustic emission in rocks in situ by the ULF atmospheric electromagnetic field.

Izvestiya, Physics of the Solid Earth, 2006

A phenomenological model for emission responses of a geophysical medium is proposed for the descr... more A phenomenological model for emission responses of a geophysical medium is proposed for the description of the general variation patterns of seismic and acoustic emission signals from rock masses and loaded samples. In this model, based on simplified equations, the responses of the medium to pulsed vibrational and electric fields are examined together with the relaxation process; in the simplest particular case, the latter can be described by the Omori law. PACS numbers: 91.30.Ab

physica status solidi (b), 2006

High precision measurements of Hall R H (T) and Seebeck S(T) coefficients have been carried out f... more High precision measurements of Hall R H (T) and Seebeck S(T) coefficients have been carried out for the first time on single crystals of rare earth dodecaborides RВ 12 (R -Ho, Er, Tm, Lu) at temperatures 1.8 -300K. Low temperature anomalies associated with antiferromagnetic phase transitions in HoВ 12 , ErВ 12 and TmВ 12 compounds have been detected on the temperature dependencies of R H (T) and S(T). The estimated values of charge carriers' mobility allowed us to conclude about the appreciable influence of spin fluctuations on the charge transport in these compounds with B 12 atomic clusters.

Materials Science and Engineering: A, 2009

The idea of the work is to demonstrate that impacts of crossed electric and magnetic fields (Cr.E... more The idea of the work is to demonstrate that impacts of crossed electric and magnetic fields (Cr.EMF) are applicable to study the rate of internal fracturing processes in loaded rock specimens. Our previous experiments with rock specimens loaded by a press have revealed the effect of acoustic emission (AE) activity increment caused by electric pulses. The experiments have been held on a noiseless rheological machine available at Bishkek Geodynamic Research Center-RS RAS. We analyzed the temporal dependence of AE activity during exposure to crossed electric and magnetic field; the compressive load being constant. The effect of AE stimulation by power pulses (triggering) has been verified. AE measurements have confirmed the existence of explicit response to both kinds of Cr.EMF pulses: solitary pulses with major amplitudes of E and B and periodic long-term pulses of minor E and H amplitudes. The comparison of recent and previous results on AE triggering by external electromagnetic (EM) fields has demonstrated that two modes of activation can be distinguished. Both kinds of AE variations (responses) are manifestations of change in internal friction (microcracking and kinetics of other defects).

Contributions to Plasma Physics, 1994

Continuous geoacoustic emission (GAE) measurements were acquired using a three-component geophone... more Continuous geoacoustic emission (GAE) measurements were acquired using a three-component geophone placed in a borehole at a depth of near 1000 m at Petropavlovsk-Kamchatsky starting in August 2000. Using geophones consisting of magneto-elastic crystal ferromagnetic sensors, and installed at such a depth allows measurement of natural geoacoustic background with signal amplitude less than 1×10 -4 m/s 3 in frequency band from 3 to 1500 Hz. According to the data from a 4-year survey period the characteristics of diurnal geoacoustic variations change before every earthquake with MLH≥ 5.0 that occurs at a distance of less than 300 km from the observation point or before each earthquake with MLH≥5.5 occurring at distance R≤550 km from the observation point. The changes in GAE regime correlate with the strongest earthquakes that occurred during survey period. Measurements of the natural electromagnetic field of the Earth were carried out simultaneously with the help of an underground electric antenna. The behavior of GAE in aseismic periods appears to be related to the effect of diurnal variations of the natural electromagnetic field.

An effect of high-power electromagnetic pulses of magneto-hydrodynamic (MHD) generator on the sei... more An effect of high-power electromagnetic pulses of magneto-hydrodynamic (MHD) generator on the seismic regime over the Northern Tien Shan and Pamir regions has been studied. It was found that occurrence of local earthquakes after firing runs of MHD generator became higher than before them. An increased level of seismic activity was observed within 3 to 6 days after the firing