Spectral signature of geocenter motion observed with DORIS and expected from geophysical data. Colour code: light blue: ignwd03; blue: ignwd05; pink: ina04wd01; brown: lcamd02; green: geophysical. A slope equal to -1 is the signature of white noise (from the report of the IDS center).
For every i-point of the reference network the geodetic height H G relative to the reference ellipsoid (for GPS that is WGS-84 ellipsoid with a=6378137m) is determined by the use of GPS/GLONASS measurements and the normal height H is estimated by the geometric leveling in the regional reference system (the Crownstadt height system for Russia). At these points an equality of the geodetic heights H G and the heights, obtained as a sum of quasigeoid height and a normal height H , should be achieved. Then we can write the next equations: (1) where is a quasigeoid height, a e – estimated correction to the semimajor axis of the WGS-84 reference ellipsoid relative to the general Earth ellipsoid, H i - an estimated correction to the regional system of normal heights relative to the general Earth’s ellipsoid. The joint solution of the unlinear equations (1) for all ground sites, where the given set of measurements is available, will enable to estimate corrections to the national and to continental systems of normal heights and to determine the corrections to the semiaxis of the general Earth ellipsoid. The surface of the general Earth ellipsoid and its potential U 0, considered like a normal one, determines the height reference system.
The diagram of differences between quasigeoid heights, estimated only by the EGM-96 gravity model, and quasigeoid heights, obtained with the use of mean gravity anomalies by trapeziums 5’ 7.5’ in central zone. The residuals are at the level of 0.4-0.5 m. A profile of differences of quasigeoid heights, estimated by the EGM-96 gravity model and by the detailed gravimetric data, along the 60 o parallel of Russian territory Longitude Diffr.
Isolines of corrections for transformation to the global system of normal heights (European network) Isolines of differences between the meanings of quasigeoid heights calculated 1) with the use of gravity models (EGM-95 and GAO-98) and 2) as a difference of an ellipsoidal height, obtained by GPS measurements at the core sites of the network, and a normal height, obtained from the precise leveling.
The basic gravimetric network (I) пункты основной гравиметрической сети 1 класса basic gravimetric sites main gravimetric sites (I)
Information on the Researches at the Geodynamic Test Area of the United Institute of High Temperatures of the Russian Academy of Sciences ( OIVT RAS) The main objectives of researches are geodynamic studies of Tien-Shan. These studies are of great social significance and directed to the reconstruction of the up –to-date strained-deformed state of the litosphere. Due to high activity of the endogenous and exogenous geologic processes in Tien-Shan the disasters like earthquakes, slides and oth., are take place. These studies are carried out by the Scientific station of the OIVT RAS at Bishkek with a participation of more than 20 organizations of the USA, Kyrgyzstan and Kazakhstan. The complex of investigations consists of: 1. Monitoring of seismic conditions with the use of 10 telemetric seismostations of the KNET network, located in a region of the Northern Tien Shan. The seismological network KNET has been established in 1991 and is equipped with 10 wideband automatic stations of PASCAL type, working in a real time. Digital data of this network are regularly transmitted to the San-Diego University of California. Studies of the spatial-temporal distribution of earthquake hypocenters are the main objective of this seismic monitoring. 2.Studies of recent crustal movements with the use of space geodesy technique and GPS measurements.GPS network in Tien Shan region was established in 1992. Subsequently it was expanded to the Kazakhstan platform and now this network consists of 10 permanent and 355 points of periodic measurements.GPS and seismic data have been also compared with the data of magneto–telluric sounding, and in particular with a geometry of the surface of a crustal conducting stratum, singled out under the Tien Shan. 3. Electro-magnetic monitoring on the base of power current sources with the use of sounding methods at the distant and at the nearest zones for the purpose of deformation processes studies at the depths till 25 km. 4. Studies of the depth structure of the Earth’s crust and upper mantle of Tien Shan. For this purpose Magneto-Telluric Sounding (MTS), including regional profiles, running across Tien Shan, and detailed sounding at the recent active faults, are carried out. Observations with the use of American low frequency equipment LIMS have been carried out at 20 points, that allowed to increase the depth of investigations till 120-140 km and to study of the upper mantle structure peculiarities.
CRDF RQ1-2239 Studies and Predictions of the Volcano ELBRUS Behavior. 1. Geophysical investigations: - determination of positions and dimensions of the Mt.Elbrus and Shasta's magma-chambers on the base of analysis of gravity and magnetic surveys and stationary earth tide gravity and tilt observations; - investigation of the dynamics of the magmatic chamber evolution on the base of repeated absolute and relative gravity and GPS-observations (determination of vertical and horizontal speed of the Earth's crust blocks displacement along the selected profiles) 2. Geodetic investigations including GPS-measurements. We expect that if magma-chamber exists under the volcano, the dynamics of its evolution ("upwelling" or "sinking") could be fixed by systematic GPS - observations. Data on velocities of the uplift derived with a help of GPS-observations will be compared with the results of repeated highly accurate absolute and relative gravity observations and this will permit to specify the uplift mechanism which related to specify the uplift mechanism which related to evolution of magma-chamber. Based on these investigations the formation history of volcanos Elbrus, Shasta, Lassen (CAUCASUS area) would be reconstructed; the features of chemical composition, evolution and petrogenesis of the lavas which make up the volcanic centres would be revealed; the forecasting pattern of volcanic eruption will be given. Russian team of this Project will be represented by the Laboratory of Petrology of the IGEM; RAS, and by the local Geologic survey expedition ( Essentuki).
Тектонические блоки Евразийской плиты по спутниковым данным
Гипотетическое представление о вращении континента
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