1056 ISSN 1028-334X, Doklady Earth Sciences, 2016, Vol. 470, Part 2, pp. 1056–1058. © Pleiades Publishing, Ltd., 2016. Original Russian Text © A.K. Nekrasova, V.G. Kossobokov, 2016, published in Doklady Akademii Nauk, 2016, Vol. 470, No. 4, pp. 468–470. Unified Scaling Law for Earthquakes in Crimea and Northern Caucasus A. K. Nekrasova a * and V. G. Kossobokov a,b,c Received November 12, 2015 Presented by Academician A.D. Gvishiani November 7, 2015 Abstract—This study continues detailed investigations on the construction of regional charts of the parame- ters of the generalized Guttenberg–Richter Law, which takes into account the properties of the spatiotempo- ral seismic energy scaling. We analyzed the parameters of the law in the vicinity of the intersections of mor- phostructural lineaments in Crimea and Greater Caucasus. It was shown that ignoring the fractal character of the spatial distribution of earthquakes in the southern part of the Russian Federation can lead to significant underestimation of the seismic hazard in the largest cities of the region. DOI: 10.1134/S1028334X16100032 INTRODUCTION Systematic analysis shows [1] that the maps of probability estimates of seismic hazards undoubtedly contradict the actual occurrence of strong earth- quakes. In particular, investigations on the character- istics of strong earthquakes in various energy bands and various seismically active regions provide evi- dence that it is necessary to take into account the lin- ear size of the domain considered in the research L 0 , which is usually ignored. Generalization of the classi- cal Guttenberg–Richter relation [2] for the annual number of earthquakes N(M, L) in the range of mag- nitudes M – ≤ M ≤ M – and sizes L – ≤ L, L 0 ≤ L – can be presented in the form of the unified scaling law for earthquakes (USLE) [3, 4]: , (1) where coefficients A and B have the same physical sense as in the Guttenberg–Richter relation and coef- ficient C characterizes the locally fractal dimension of the media of earthquake epicenters. Coefficient A is related to one year; it characterizes the expected num- ber of earthquakes with magnitude 5.0 in the seismi- = + - + 10 10 log ( , ) (5 ) log NML A B M C L cally active region with a linear size of one unit length in the region with size L 0 × L 0 . Previously, the analysis of the USLE parameters was performed for global and some regional earth- quake catalogues [4–9] to clarify the traditional esti- mates of the seismic hazard and risks of earthquakes. In this work, we perform for the first time analysis and mapping of the USLE coefficients in the territory of seismic active regions in the southern European part of the Russian Federation. We use a modification of the algorithm for estimat- ing the USLE coefficients, which allows us to perform additional stabilization of the computational results. The algorithm and a scheme of its application are described in detail in [4]. DATA Seismicity on the territory of Crimea and Northern Caucasus within the boundaries of the regions in the directory Earthquakes of Northern Eurasia for 1998–2008 is systematically presented by the events of various amplitudes. The recurrence graph in these regions are approximated to a high accuracy by formu- las log 10 N = –0.13M² + 0.054M + 2.75 (R² = 0.996) in Crimea and log 10 N = –0.28M² + 1.25M + 2.53 (R² = 0.994) in Northern Caucasus (here N is the number of earthquakes with magnitude M and greater for 1998– 2008). In order to calculate the USLE coefficients, we used the events with a magnitude of 2 and greater, rep- resentation of which in the catalog is quite high. GEOPHYSICS a Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Sciences, Varshavskoe sh. 2, Moscow, 113556 Russia b Geophysical Center of the Russian Academy of Sciences, ul. Molodezhnaya 3, Moscow, 119296 Russia c Institut de Physique du Globe de Paris, Paris, France *e-mail: nastia@mitp.ru