ON THE GEOELECTRICAL DIFFERENCE BETWEEN THE KURIL‐KAMCHATKA AND BERING SEA SEGMENTS OF THE PACIFIC TRANSITION ZONE

Abstract

The data from the regional magnetotelluric sounding profiles Severny and Yuzhny (northern and southern, respectively) was analyzed and interpreted. The profiles were located on several sites of the eastern coast of Kam‐ chatka, which differ in tectonic structure and geodynamic conditions. The southeastern region covers the Kuril‐ Kamchatka segment of the Pacific transition zone, which corresponds to the active continental margin, while the northeastern region includes the passive continental margin. Geoelectrical sections were obtained along the regional profiles to a depth of about 80 km. The identified anomalies of electrical conductivity were compared with the data obtained by other geophysical methods (specifically, the data on gravity and anomalous magnetic fields). The com‐ parative analysis of the geoelectrical sections shows that electrical conductivity changes gradually in the northeastern region, while the structure of the southeastern region is represented by blocks differing in geoelectrical properties. The conducting horizon of the lithosphere lies at different depths in different parts of East Kamchatka. The south‐ eastern section shows the roof of the lithospheric layer closest to the land surface.

Keywords

• magnetotelluric sounding
• regional profile
• deep geoelectrical model
• lithospheric conductive layer
• pacific transition zone
• numerical simulation