POST SEISMIC DEFORMATION AND GEOMAGNETIC VARIATION IN EPICENTRAL AREA OF THE RUDBAR EARTHQUAKE OF ۱۹۹۰

Results of experimental studies of evolution of the seismotectonic process in epicentral zone of the Rudbar earthquake of June, ۲۰, [۹۹۰, M = ۷.۳ during aftershock period are considered. By means of high precision repeated geodetic, magnetometric and seismometric measurements it was detected, that after the main shock(August -September) the stress-deformed state of epicentral zone underwent an active modification. On the background of linear changes (trend) it were observed variations of distance with a short period. The amplitudes of variations decreased on a measure of fading of aftershock activity. The connection between variations of distance and local geomagnetic field with the close strong aftershocks was observed in a space and time. Deformational processes under general resemblance had differences in different places, connected to a particularity of an aftershock phase - by-rather quick changes of a source area structure, in contrast with a period of earthquake preparing. After a main quake, during an aftershock activity, the blocks of different scale are formed in superficial parts of the Earth crust, inside and on which boundaries the quick redistribution of stress took place.