Deep structural and tectonic features of focal zones of 21st century earthquakes in the northwestern part of the Greater Caucasus

E.A. Rogozhin1,2, A.V. Gorbatikov1, M.Yu. Stepanova1, Yu.V. Kharazova1, A.I. Sysolin1, A.A. Rybin1

1 Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia

2 Federal Research Center – Geophysical Survey of Russian Academy of Sciences, Obninsk, Russia

Corresponding author: M.Yu. Stepanova, e-mail: maris.terras@gmail.com

Abstract. The summation of the available and newly collected data on the shallow and deep structure and modern geodynamics of key regions of the north-western part of the Greater Caucasus was carried out. The fault-block model of this mountain-folded structure and the nature of seismogenic displacements along the faults on its north-western pericline have been developed. The reasons for the abrupt change of the folded-block structure in the area of the Anapa seismic-generating flexural-discontinuous zone were clarified. Detailed models of the shallow and deep structure were compiled for a number of the most important seismic-generating structures in the North-Western Caucasus, which gave rise to the Nizhnekubansky II earthquake on November 9, 2002 with M = 4.7 and Su-Psekh event on December 10, 2012 with Mw = 4.3, Pshekhsky earthquake on November 15 2004 in the Krasnodar Territory with M = 4.6. Based on the results of field geological and geophysical surveys, volumetric geodynamic and seismotectonic models of seismo-generating structures were constructed. The morphology of regional tectonic structures at depth for their comparison with the focal parameters of three strong earthquakes was investigated by microseismic sounding method.

Keywords: hypocenter deep structure, microseismic sounding method, earthquake mechanism solution

About the authors

Rogozhin Evgeny Aleksandrovich − Professor, Doctor of Geological and Mineralogical Sciences, Chief Researcher, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences. Bolshaya Gruzinskaya str., 10-1, Moscow 123242; Federal Research Center – Geophysical Survey of Russian Academy of Sciences. Lenina av. 189, Obninsk, Kaluga region, Russia, 249035. e-mail: eurog@ifz.ru

Gorbatikov Andrey Veniaminovich − Candidate of Physical and Mathematical Sciences, Leading Researcher, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences. Bolshaya Gruzinskaya str., 10-1, Moscow 123242. e-mail: avgor70@mail.ru

Stepanova Marina Yuryevna − Candidate of Physical and Mathematical Sciences, Senior Researcher, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences. Bolshaya Gruzinskaya str., 10-1, Moscow 123242. e-mail: maris.terras@gmail.com

Kharazova Yulia Vyacheslavovna − Research Fellow, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences. Bolshaya Gruzinskaya str., 10-1, Moscow 123242. e-mail: uh69@mail.ru

Sysolin Alexander Ivanovich − Leading Engineer, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences. Bolshaya Gruzinskaya str., 10-1, Moscow 123242. e-mail: alexandr.sysolin@gmail.com

Rybin Aleksey Aleksandrovich − Leading Engineer, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences. Bolshaya Gruzinskaya str., 10-1, Moscow 123242. e-mail: aar@ifz.ru

Cite this article as: Rogozhin E.A., Gorbatikov A.V., Stepanova M.Yu., Kharazova Yu.V., Sysolin A.I., Rybin A.A. Deep structural and tectonic features of focal zones of 21st century earthquakes in the northwestern part of the Greater Caucasus, Voprosy Inzhenernoi Seismologii (Problems of Engineering Seismology), 2019. V.46, No. 1. P.60–75. [in Russian]. DOI: 10.21455/VIS2019.1-5

English translation of the article will be published in Seismic Instruments, ISSN: 0747-9239 (Print) 1934-7871 (Online), https://link.springer.com/journal/11990), 2020, Volume 56, Issue 1.