The state gravity map of Russia on the Barents sea and western portion of the Kara sea.

V. Zhuravlev, I. Frantsuzov, V. Vasiliev.
JSC Marine Arctic Geological Expedition.

Russian

Abstracts


1. Gravimetric isoline maps is a perfect way to present abnormal gravitation field structure. In Russia (like in former USSA) these maps were drawn after interdepartament instructions, based on long-term experience. These instructions establish strict standards of scaling, metering errors, detailedness of field study and isoline cut. Gravimetric maps corresponding to all these standards receive national status and can be used by various state departments for solution of applied or scientific problems.

2. State gravimetric maps are made for standard international ruling sheets of the scale 1:1000000 and 1:2000000. The co-ordination of all survey data and their correspondence to the state standards is checked.

3. The State gravimetric map was started in USSA in the middle 60-s, under supervision of N.Sazhina and V.Fedynsky (VNIIGeofizika, Moscow). But conditional sheets of the State Gravimetric map appeared only in the early 80s. By that moment the method of above-water survey has developed, metering errors of gravimetric survey has decreased and marine survey data, taken according to the regular greed, has been sufficiently accumulated. The first in the USSA State Gravimetric Map 1000 sheets covering sea area were made up by the MAGE specialists after the above-water survey data, acquired by the expedition in the Barents sea. Later, in 1991-1992, the first set of the State Gravimetric Map 1:200000 sheets were drawn, based on the Kola shelf of the Barents sea above-water survey data.

4. By today MAGE has accomplished the State Gravimetric Map 1:100000 sheets, covering the Barents sea, the northern part of the Kara and the western part of the Norvey seas. The second set of the map 1:200000 sheets covering the north of the White sea is coming.

5. The observed gravity force field is quasi-stationary. In geological interpretation of gravimetric materials (maps and diagrams) the direct and indirect gravimetry problems are implied. Density modeling is the most frequently used method, which mean 2D and 3D model matching, whose gravitational influence is identical to the observed field. The reliability of models depends on the quality of gravimetrical measurements and on other geological and geophysical materials available. Consequently, if new a priori data are received, geological model can be precised.

6. MAGE specialists have used the gravimetrical maps 1:100000 for the regional study of the Barents-Kara region geological structure to delimit the struclural-tectonic regions, to estimate the sedimentary cover thickness of the sea areas and to determine possible mineral deposits. In the tectonic map of the region the main tectonic elements borders are laid after seismic and gravimetric data. Tectonic abnormalities mapping, salt-dome structures allocation and delimitation in Nordcap and Olga flexures were also done after gravimetric maps.


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Created by Vlad Vasiliev on 16 Nov 2002
Last modified on 2 Dec 2002


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