MONITORING OF GEODYNAMIC ACTIVITY OF THE ROSTOV NUCLEAR POWER PLANT REGION WITH GPS TECHNOLOGY

A description of the seismotectonic situation of the area at the Rostov Nuclear Power Plant (NPP) industrial site area is given. It is noted that despite the location of the NPP within the stable platform area, there is a possibility of rare strong seismic events in the zones of intersection of deep faults of the north-western and north-eastern directions, where superdeformations of the crust (2 × 10−5... 7 × 10−5) with a formation time from several days to several months are possible. Estimation of the maximum possible magnitude for faults of an unclear degree of tectonic activity Мmax, performed by the Geophysical Service of the Russian Academy of Sciences (GS RAS) according to the maximum gradients of the geoidal height field gives Мmax a magnitude value of up to 5.2. Taking into account the expression for the empirical deformation radius of Dobrovolsky RD = 100.43M, magnitude 5.2 approximately corresponds to a radius of 170 km, within the IAEA requirements (up to 200 km). For the area of the NPP industrial site location with such radius, where earth’s surface deformations are possible, scientifically based data on the geodynamic situation should be obtained. The project of the GPS network developed by the GS RAS was considered in order to assess seismogeodynamic activity of the Rostov NPP location area. The efficiency of the GS RAS GPS network can be improved by installing five additional permanent GPS stations of the Southern Scientific Centre of the Russian Academy of Sciences (SSC RAS) and introducing a new technology for processing satellite measurements based on multidimensional statistics. An example of the current GPS monitoring system of the SSC RAS, created jointly with Yuzhmorgeologiya JSC and Kuban State University on the basis of a regional GPS network in the Taman Peninsula region, is presented. In the course of observations during the period of increased seismic activity in 2017–2018 42 earthquakes were recorded, of which a catalog of 12 seismic events with magnitudes from 3.5 to 4.7 and epicenters on land and in the Azov and Black Seas was compiled. The definition of the integrated indicator of the stressed-deformed state of the crust is given on the basis of mathematical methods of multidimensional statistics. Analysis of time variations of the integrated indicator value in the low-frequency band shows an increase in its amplitude 20–40 days before the earthquake within the GPS network.

GPS observation, crust deformation, earthquake precursors