Name of laboratory:  VARIATIONS OF GEOPHYSICAL FIELDS.

Foundation history of the laboratory:
The Laboratory "Variations of geophysical fields" (VGF) was organized simultaneously with the organization of Seismology Institute on October 1, in1966, as a part of the Earthquake Prediction Department. The Department was managed by academician Gani Mavlanov, and the laboratory by geophysicist Manop  Gofurov. In 1971, candidate of geological-mineralogical sciences Ibragimov Rashad, who had been worked as a senior researcher at the laboratory of "Seismotectonic regionalization", became head of the laboratory. From that time the name of the laboratory was renamed to «Variations of geophysical fields and seismotectonics». The name was kept until 1977. On September, in 1977, the Institute had accomplished a great structural reformation. While that period, the staff of the Institute increased dramatically. Moreover, there opened 7 new laboratories; network seismic prediction stations were expensed by the government. On the basis of the laboratory "Variation of geophysical fields and seismotectonics" was organized two new laboratories such as “Variations of geophysical fields” and "Seismotectonics". Since 1977, the Laboratory "Variations of geophysical fields" has been headed by a doctor of physics and mathematics sciences, a professor, an academician of the Academy of Sciences of Uzbekistan Kharbay Abdullabekov.
Currently, at the laboratory work an academician, a doctor of sciences, 2 candidates of sciences, and a doctor of philosophy, a MS and a laboratory assistant. There are instruments and equipments for the geophysical researches and automatic processing of the received information.
1.    KharbayAbdullabekov, a doctor of phys-math. sciences, a professor, an academician of Academy Sciences of the Republic of Uzbekistan.
2.    Sabitjan Maksudov, a doctor of phys-math. sciences.
3.    Mirsaid Muminov, a candidate of phys-math.sciences.
4.    Ahmadjan Tuychiyev, a candidate of phys-math. Sciences.
5.        Valijon Yusupov, a doctor of philosophy (PhD).
6.    Kamola Sagdullaeva, M. B. S.

Main research directions of the laboratory:
Study of the electromagnetic phenomena in the earth's crust and the space-time features of the occurrences of the complex of earthquake precursors. Development of theoretical basis of the earthquake prediction system and geophysical models of the earthquake preparation processes. Study the form effect of the reservoirs operations, underground gas storages, gas fields, etc. on the nature of the variations of electromagnetic fields.
Scientific achievement:
The following results are unique in the world practice, many of which are obtained in the world practice for the first time:
 *Anomalous change of the magnetic field associated with the operation mode of the underground gas storage facility was identified for the first time;
*The researches are carried out in the area of the Charvak Reservoir, in the zones of gas and oil fields such as Shurtan, Pamuk, Zevarda, Kokdumalak, etc. and in the epicenters of strong earthquakes such as Tovoksayian, in 1977, Isfara-Batkenian, in 1977, Nazarbekian, in 1980, Gazlian, in 1976 and in 1984, Chimianian, in 1982, Papian, in 1984, Khamzabodian, in 1985, Izbaskanian, in 1992, Kamashinian, in 1999 and in 2001, Kansian, in 2011, Marjanbuloksian, in 2013 and etc.
* In the epicenter of the Nazarbayev earthquake on December 11, 1980 (M=5, 5) for the first time the slow reduction of the geomagnetic field was marked simultaneously with the weakening of the seismic regime in the hearth;
* For the first time in the world practice, directly above the hearth of the strongest Ghazal earthquake on may 17, in 1976, with a magnitude of M=7.3, executed high-precision measurements of the magnetic field, at the time and after the main shock. New was the result of distortion of the amplitude of the bay-like changes in the magnetic field over the epicenter of the earthquake to 70-80%. Analogous distortions of bay-like variations were also found for the Chimyanian earthquake on May 6, 1982 with a magnitude of M=5.8;
* At the East Fergana on the Geodynamic Polygon for 13 years had been repeatedly carried out areal magnetic surveys at 40 points where located evenly over the area regularly at a frequency of 15 days, as a result of research it was possible to trace the appearance, development and disappearance of several areal magnetic field anomalies associated with specific earthquakes (Alay on November 2, in 1978, M=6,8; Chimyanian on May 6, in 1982, M=5,8; Papian on February, in 1984, M=5.5.);
• On the Eastern Fergana on the Geodynamic Polygon were also marked numerous short-term magnetic anomaly intensity from a few to 23 nTl. Outstanding interest is the anomalous change obtained at the Andijan station at a distance of 120-130km from the epicenter of the Alay earthquake on November 2, 1978(M=6.8), the intensity of 23ntl. Peculiar time is a week. The earthquake was predicted six hours before the shock by the help of these and other complex observations. The content of the article published in the Geophysical Magazine of the American Astronomical Society was commented in detail in the newspaper “The Times” on January, in 1982;
* the zone with anomalous electrical conductivity of the earth's crust passing in the sublatitudinal direction along the South Fergana deep fault in the direction of Andijan-Kuvasay-Isfara-Kayrakkum-Central Kyzylkum and further in the South-West direction is allocated;
* Carried out research in the territories of evolved oil and gas fields. For example, on the territory of the Shurtan gas field, the change in the field is clearly correlated with the volume of gas produced (Q) and the change in reservoir pressure (P). The correlation coefficient between the change in the local magnetic field and the operating parameters is 0.98 and 0.95 for Q and P, accordingly. Analogous results were taken at the geomagnetic research on the territories Pamuk-Zevardinian group of oil and gas structures, Kokdumalak fields, Khauzak-Shady;
• Based on the analysis and generalization of the results of long-term studies of variations in the geomagnetic field, spatial-temporal and amplitude-frequency features, sometimes even patterns of manifestation of four types of anomalous variations associated with the stages of earthquake preparation, were revealed. Three types of them are extended-term, medium-term and short-term manifested before earthquakes, and the fourth type is associated with aftershock afterworking;
* the results of these studies and the data that obtained at the geodynamic polygons of Uzbekistan gave opportunity to find a straightforward empirical relationship between the duration of the manifestation of long-term and medium-term precursors and the magnitude of earthquakes;
* on the basis of 4 types of anomalous variations of electromagnetic fields, identified by long-term field experiments, associated with various stages of preparation and manifestation of earthquakes, 4-stage geophysical model of earthquake preparation processes is proposed.
In the consequence, occurred the great event: there are created a large of seismologists–magnetologists and geophysicists scientific schools in Uzbekistan.
Since 1966 till these days, employees of the laboratory of Variation of Geophysical Fields published more than 600 scientific articles, about 30 monographs, achieved 8 certificates of authorship and patents for inventions; defended 3 doctoral and 10 master's theses.
The most important publications of the laboratory:
1.    Abdullabekov K. N., Maksudov S. H. Variations of geomagnetic field of seismoactive regions. Ed. Fan, Tashkent, 1975, 128 p.
2.    Electric and magnetic precursors of earthquakes. Publishing House "FAN", Tashkent, 1983, 135 p. (collection).
3.    Abdullabekov K. N. Electromagnetic phenomena in the earth's crust. Ed. Fan, 1989, 232 p. (Monograph in 1990 translated into Chinese and published in Beijing, 198 p.).
4.    Abdullabekov K.N.  Electromagnetic phenomena in the Earth’s Crust A.A.Balkema, Rotterdam, Netherlands, 1991, 169 p.
5.    Shapirov V.A., Muminov M.Yu., Abdullabekov K.N., High precision magnetometry for earthquake prediction in Uzbekistan: 91 forecasts between 1982 and 1992.   In: Electromagnetic Phenomena Related to Earthquake Prediction, TERR Magnetic field variations of crystal origin measured in the Fergana Valley of Uzbekistan, reflecting seismotectonic dynamics. APUB, Tokyo, 1994, 37-42 p.
6.    Shapirov V.A., Muminov M.Yu., Khadzhyev T.Kh., Abdullabekov K.N. Magnetic field variations of crystal origin measured in the Fergana Valley of Uzbekistan, reflecting seismotectonic dynamics. Prediction TERRAPUB, Tokyo, 1994, 43-49 p.
7.    Seismic zoning and earthquake prediction in Uzbekistan Monograph. Ed. Hydroingeo, Tashkent, 2002, 132 p. (collective).
8.    Abdullabekov K. N., Usmanova M. T. Features of manifestation of strong earthquakes in time and space. DAN, Republic of Uzbekistan, 2003, №3, 60-64 p.
9.    Abdullabekov K. N. Geophysical model of earthquake preparation processes. DAN of the Republic of Uzbekistan, 2008, No. 2, 49-52 p.
10.    Abdullabekov K. N., Maksudov, S. Kh. Muminov M. Y., Tuychiyev A. I. The Results of the years of the studies of seysmomagnetic effect in Uzbekistan, proceedings of the IX international scientific - practical conference "Analysis, forecast and management of natural risks in the modern world GEORISK -2015" (Moscow, 14-15 October, Volume 1, 433-439 p).
11.    Muminov, M. New version of the Central Asia geodynamic model. Geology and mineral resources, 59-64 p.
12.    Abdullabekov K. N., Tuychiev A. I. Features of the manifestation of earthquake precursors with the distance and size of geotectonic blocks. In the proceedings of the VII international Symposium.  "Problems of geodynamics and Geoecology of intracontinental orogens".  19-24 June 2017. Bishkek, 268-272 p.
13.    Abdullabekov K.N... Maksudov S. H., Tuychiev A. I., Yusupov V. R. Local variations of geomagnetic field of technogenic and geodynamic nature in the area of Charvak reservoir. "Exploration and protection of mineral resources". Russia 2018, 35, 27-32 p.
14.    Yusupov V.R. Anomalous variations of geomagnetic field in the Сharvak polygon. International journal of Geology of the Earth and Environmental sciences.  India, 2018. vol. 8, №1. 23-30 p.




2018 год © Институт Сейсмологии им А. Г. Мавлянова
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