Electrical Conductivity Models of the Earth Crust and Upper Mantle of NE Eurasia were studied by the Russian and Chinese scientists participating in joint International Project . It was decided that the Tian-Shan orogenic structure is the most important object for the project.

This structure is partitioned on the western (CIS) and eastern (China) parts. Tian-Shan gives a unique possibility to study the effect of Cenosoic geodynamic activation on the crustal electrical conductivity models. The latters were constructing by help of the Russian-Chinese magnetotelluric data bank compiled in frames of the Project. The bank was the basis of the field data interpretation. A key point of study was the separation of the deep and surficial conductivity anomalies. Russian scientists passed their technique of the thin-sheet computer modeling of the sediment basins effect on the magnetotelluric impedance, to Chinese participants of the Project. By help of that technique a modeling was carried out using both Russian and Chinese geological and geophysical information about the thickness and conductivity of the sediment cover in Tarim, Dzhungar, Chu and Ili sedimentary basins. The main feature of the Earth crust of the Tian-Shan is a thick well-conducting mid-crust layer at depth of 20-40 km. A fluid explanation of the nature of the layer was developed in the Shirshov Institute and Moscow University using the Russian-Chinese data bank. Dehydration of hydrated minerals (e.g. amphibolite facii) was considered as one of the most important sources of fluid. It was estimated that the volume of released water could provide the conductivity increase up to 0.1 S/m, that is to the values obtained by MT sounding. An International Project for reuse of the submarine cable Nakhodka-Naoetsu was carried out by the Shirhov Institute of Oceanology, University of Tokyo and Pacific Institute of Oceanography. The cable was used for solving of two problems:

1. Monitoring of sea-water motion.

2. Estimation of the integral resistivity of the lithosphere of Sea of Japan.

Experimental data were processed by means of modern robust technique.

Thin-sheet modeling plays a key role in the interpretation of the observed data. An estimation of the galvanic link of the asthenosphere and water layer was found that is a measure of the lithosphere resistivity. Correlation of the cable voltage and water transport was obtained as well.

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