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Coda Q has been studied in the North-West Caucasus region using 267 earthquakes and 17 stations from the network of the Geophysical Survey, Russian Academy of Sciences. This is the first Qc study for the region using such a large dataset. The average frequency-dependent coda Q relationship is Qc=90±21•f 1.02±0.11 . This value compares closely to other similar tectonic areas in the world where the same processing parameter had been used. Three specific zones, two in the Greater Caucasus tectonic area and one east of the Ciscaucasian trough area, were studied separately. There was a clear difference in Qc between the zones, particularly for the Ciscaucasian trough area which shows a higher Qc than the 2 other zones. However, the difference between the zones became smaller when using long lapse times tending to give a constant Qc as a function of lapse time. For longer lapse time it is assumed that a large part of the coda waves passes the mantle. The 2 zones in Greater Caucasus now had a similar Qc while the East zone in the Ciscaucasian trough still gave the highest values. We contribute this difference to differences in attenuation in the mantle under the two tectonic areas. In our area, there is then a clear difference in Qc for the 3 study areas in the crust but in the mantle the difference is mainly between the two tectonic zones.

The methods and results of seismic hazard zoning are investigated for the Russian Federation territory and abroad. The input data used in the zoning procedure, aimed at revealing the boundaries of areas with stable seismic intensity attenuation parameters have been analyzed. The zoning procedure has been developed for determining the boundaries of territories, within which the macroseismic field parameters (i.e., the coefficients in N.V. Shebalin’s equation; the orientation of the elliptic isoseist axes, as well as the ratio of their semi-axes) show close values in each point. Examples are given in distinguishing zones characterized by quasi-stable parameters for separate regions, as well as in calibrating the computer model of the macroseismic field. The case studies are considered in the presence of a complete set of input data and under conditions of their insufficiency. The efficiency of the macroseismic field calibrated models application in the Extremum system in order to increase the reliability of near real time earthquake loss estimations is shown.

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The instrumental and macroseismic data on the earthquake of August 7, 2016 with Mw=4.6, which occurred near the city of Mariupol (Ukraine) and was felt in 47 settlements at distances up to 458 km from the epicenter with an intensity of 2 to 5 at MSK-64 scale , are presented. The earthquake occurred in the area of the North Azov fault at the southern border of the East European platform. The spatial distribution of macroseismic data made it possible to construct a map of isoseists of Ii=3 and 4. The focal mechanism is constructed and a strike-slip motion type in the focus is determined.

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