2D and 3D Deformation Field over Bishkek Proving Ground Developed on the Base of the GPS Data. Manifestation of the Deformation Field in Electrical Resistivity Variation Pattern (Project proposed to start)(Geoscience)
Organization who response for the project from Russian side - The Research Station, RAS; The Geophysical Center, RAS Principal Investigators (Russia): Prof.A.M.Fridman, prof. G.A.Sobolev, prof. V.A.Zeigarnik
Organization who response for the project from US side - Massachusetts Institute of Technology
Principal Investigators (USA): Prof. Bradford Hager, Prof. Thomas Herring.
Description The Bishkek Proving Ground (BPG), the Research Station, Russian Acad. Sci. has been developing since 1982.
The BPG covers the Kirgizian Tien Shan and adjacent areas. The Tien Shan, due to its modern geodynamic activity, is a natural geological laboratory and the scientific community can observe not only static pattern but also temporal changes here. Thus, analysis of more than twenty years monitoring data on different geophysical field variations is of great interest. The data is so large that combined analysis of the whole set demands new geoinformatic technologies and different approaches. The Tien Shan can be referred to as the fine test bed for innovative ways of multi-disciplinary data aggregation and integration.
The BGP observation system includes :
- An electromagnetic sounding net consisting of 6 stationary and 15 attendant points. The stationary
points are equipped with continuous (every 20 seconds) module magnetic field measuring device. The original
power source is used to produce a train of ±600A bipolar rectangular pulses for the electromagnetic (TDEM)
soundings. At the stationary points, readings are taken 5 times a working day and the attendant ones –every
2-3 days. As a result, apparent resistivity sets over the whole BPG at different depths are available to
reconstruct the 3D electrical structure and to define the resistivity variations being a manifestation of
geodynamic processes or earthquake precursors.
- Detailed magnetotelluric (MT) and magnetovariation (MV) observations along regional and local profiles
across the Tien Shan. Since 2003, two points of continuous synchronous MT observations were
installed to provide the electrical resistivity monitoring, the Phoenix MT stations being engaged for
this purpose. The MT and MV data are used to develop the 2D and 3D electrical conductivity distribution
pattern.
- The Kirgizian seismic net (KNET) consists of 10 wide-band PASSCAL type stations. The KNET ensures
high-performance data for events with the magnitude 3 and more.
The KNET efficiency is as high as 95%. The data are transmitted to the IRIS Data Management Center in near real time regime and are then available for many institutions in different countries. On the basis of the KNET data, the earthquake focus mechanisms are calculated being an additional information to define the deformation spatial distribution. The KNET data are also included into the seismological database archives, catalogues, bulletin, and uniform digital directory.
- Regional GPS network including about 450 points over the territory of Kirgizstan, Kazakhstan and
Uzbekistan.
Here, nine points are continuous, with sampling of 30 seconds. One of these continuous nine points is included into the world GPS observation system. Since 1997, 41 points are clustered into the Bishkek subnet with frequent records (10 times a year) and dense point location. For the other points, the readings are taken 1-2 times a year. According to special agreements, the GPS data exchange takes place with Siberian and Chinese institutions. As a result, a large-scale picture can be reconstructed of the Earth plate and block motion. Fig. 6 shows a shift velocity field example derived from the above primary data.
- to derive the 2D and 3D deformation and then strain rate fields;
- to compare the deformation and different components of strain rate with the seismicity distribution;
- to define correlation between sign of the temporal resistivity variations and sign of local deformation. Special experiment will be performed using the fan-shaped electrical receiving array. An attempt will be made to answer if this correlation is valid for any depth investigated by electromagnetic soundings. Such analysis demands some primordial conception on 2D and 3D block structure. MT and MV data will be used for development of such conception along with a’priori geological data.
Project implementation really depends on cooperation with domestic and international partners. Present day data exchange with them demands net capability about 10 Mbps. Expanding cooperation would give rise to increasing the value by one or two order because scientific contacts become more multi-directional and more regular due to new initiative such as GLORIAD. High volume transfer capability should yield to realize share data, to treat the same data with alternative algorithms and software in order to test reliability of results and models and to implement contemporary IT. GLORIAD will enable solution of such type problems and will provide access to massive volume of data characterizing monitoring of various geophysical and other earth fields.
Research Station in Bishkek, RAS, is involved into scientific Program sponsored by Russian Academy of Sciences “The Development of Principal Conception for Scientific Distributed IT Medium on the Base of GRID Technology. Direction – Electronic Earth”, and expansion of IT international cooperation will promote common knowledge in geoscience.
