HISTORIC AND HOLOCENE HORIZONTAL MOVEMENTS MEASURED AT THE BAIKAL GEODYNAMIC TEST GROUND Available to Purchase

A network of GPS stations has been deployed at the Baikal geodynamic test ground by the joint Russian-French project to study the ongoing crustal movements. Processing of data obtained during three years of monitoring yielded a vector field of historic horizontal displacements for the southern and central parts of the Baikal rift system. No displacement was observed within the Siberian craton, and reference sites in western Transbaikalia showed a concordant southeastward motion. The main parameters of the vectors are in agreement with the displacements predicted on the basis of structural geology and seismology data. Instrumental measurements from 1994 to 1997 allowed us to determine the mean rate and azimuth of the opening of the Baikal rift, which are 4.5±l.5 mm/yr and about 100° N, respectively. The directions and rates of Holocene horizontal block movements in the south of the rift system, which are estimated from studies of motions on active seismogenic faults, agree with geodetic results. Extension in the central part of the rift has been directed 130° N, and the blocks of the East Sayan and Siberian craton show oblique divergent movements at about 100° N.