Deep earthquakes in the Caucasus: Reprocessed data

V.Yu. Burmin1, I.B. Shemeleva1, A.M. Avetisyan2, K.S. Kazaryan2

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

2 Institute of Geophysics and Engineering Seismology of the NASA, Gyumri, Armenia

Corresponding author: V.Yu. Burmin, e-mail: burmin@ifz.ru

Abstract. The existence of deep earthquakes in the Caucasus is extremely important both for solving problems of geodynamics and assessing the seismic hazard and seismic zoning of the region. It was previously believed that earthquakes may occur in the Caucasus, the depth of which does not exceed 150 km. However, in recent years a discussion has arisen on this problem, which is reflected in a number of publications. This article shows that in the Caucasus, in addition to crustal earthquakes, rather deep mantle earthquakes also occur. This fact, in addition to direct calculations, is confirmed by data published in the catalogs and bulletins of the Caucasus. The presence of deep earthquakes in the Caucasus significantly changes our views on the structure and geotectonics of the region. Obviously, crustal earthquakes are dominant in the seismicity of the region, but at the same time, it is obvious that mantle earthquakes also make a significant contribution to it. The fact that their share in the total number of earthquakes is much smaller than the proportion of crustal earthquakes can indicate that the crust is tougher and more fragile than the upper mantle.

Keywords: earthquakes, hypocenter, catalog, bulletin

About the authors

BURMIN Valery Yurievich – Doctor of Physical and Mathematical Sciences, Chief Researcher, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences. 123242, Moscow, ul. Bolshaya Gruzinskaya, 10, building 1. E-mail: burmin@ifz.ru

SHEMELEVA Irina Borisovna – Senior Researcher, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences. 123242, Moscow, ul. Bolshaya Gruzinskaya, 10, building 1. E-mail: shemelevs@mail.ru

AVETISYAN Andrei Mergevosovich – Doctor of Physical and Mathematical Sciences, Professor, Leading Researcher, Institute of Geophysics and Engineering Seismology named after Academician A. Nazarov NAS of RA. 3115, Gyumri, st. V. Sargsyan, 5. E-mail: avet.andrey@mail.ru

KAZARYAN Karlen Surenovich – Engineer, Institute of Geophysics and Engineering Seismology named after Academician A. Nazarov NAS RA. 3115, Gyumri, st. V. Sargsyan, 5. E-mail: g.karlen90@bk.ru

Cite this article as: Burmin V.Yu., Shemeleva I.B., Avetisyan A.M., Kazaryan K.S. Deep earthquakes in the Caucasus: Reprocessed data, Voprosy Inzhenernoi Seismologii (Problems of Engineering Seismology). 2019. V. 46, No. 2. P. 25–36. [in Russian]. https://doi.org/10.21455/VIS2019.2-3

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