DEFORMATIONS
IN EPISCOPAL BASILICA IN VARNA – EVIDENCES
OF THE STRONG
HISTORICAL EARTHQUAKES IN NORTH-WESTERN BULGARIA
©
2020 A.
Minchev1,
A.M. Korzhenkov2*,
A.N. Ovsyuchenko2,
O.V. Dimitrov3,
A.S. Larkov2,
B.K. Ranguelov4,
E.A. Rogozhin2,
N.V. Andreeva2
1 Varna Museum of Archaeology, Varna, Bulgaria
2 Schmidt Institute of Physics of the Earth, Russian Academy of Sciences Moscow, Russia
3 Institute of Oceanology «prof. Fridtjof Nansen», Bulgarian Academy of Sciences, Varna, Bulgaria
4 Mining and Geology University, Sofia, Bulgaria
*e-mail: korzhenkov@ifz.ru
Abstract. Our investigations in episcopal basilica in Varna town have revealed a number of seismic deformations in its walls: numerous shifts, tilts and rotations of the wall parts around vertical axis, as well as through-going joints cutting few stone blocks consecutively. There is revealed a cluster of (minimum) three seismic events occurred during one hundred years interval: beginning of V – beginning of VI centuries AD. Judging by kinematic indicators in the basilica constructions built of high quality stone blocks, a source of seismic motions located apparently NNE of basilica. Strong seismic oscillations which traces were revealed in later building constructions propagated apparently from SW. The seismic sources located along active faults localized north and south of Varna. Local seismic intensity of studied earthquakes was Il ≤ 9 according to MSK-64 Scale. The intensity of the seismic oscillations was increased by unfavorable ground conditions in basilica location. Obtained materials have to be considered at new seismic hazard assessment for Varna town and at creation of new map of seismic zoning of North-Eastern Bulgaria.
Keywords: Odessos, Varna, basilica, seismic deformations and destructions, kinematic indicators, ancient earthquakes, Bulgaria, archeological monuments, Early Medieval
About the authors
MINCHEV Alexander – Varna Museum of Archaeology. Bulgaria, 9000, Varna, Maria Louisa Blvd., 41. E-mail: al_minchev@abv.bg
KORZHENKOV Andrey Mikhailovich – Schmidt Institute of Physics of the Earth, Russian Academy of Sciences. Russia, 123242, Moscow, Bolshaya Gruzinskaya st., 10-1. E-mail: korzhenkov@ifz.ru
OVSYUCHENKO Alexander Nikolaevich – Schmidt Institute of Physics of the Earth, Russian Academy of Sciences. Russia, 123242, Moscow, Bolshaya Gruzinskaya st., 10-1. E-mail: ovs@ifz.ru
DIMITROV Orlin Vasiliev – Institute of Oceanology «prof. Fridtjof Nansen», Bulgarian Academy of Sciences. Bulgaria, 9000, Varna, Pervi May st., No. 40, PC 152. E-mail: ovdimitrov@io-bas.bg
LARKOV Alexander Sergeevich – Schmidt Institute of Physics of the Earth, Russian Academy of Sciences. Russia, 123242, Moscow, Bolshaya Gruzinskaya st., 10-1. E-mail: las119@yandex.ru
RANGUELOV Boyko Kirilov – Mining and Geology University. Bulgaria, 1700, Sofia, Prof. B. Kamenov st., 1. E-mail: branguelov@gmail.com
ROGOZHIN Evgeny Alexandrovich – Schmidt Institute of Physics of the Earth, Russian Academy of Sciences. Russia, 123242, Moscow, Bolshaya Gruzinskaya st., 10-1. E-mail: eurog@ifz.ru
ANDREEVA Nadezhda Vjacheslavovna – Schmidt Institute of Physics of the Earth, Russian Academy of Sciences. Russia, 123242, Moscow, Bolshaya Gruzinskaya st., 10-1. E-mail: znv@ifz.ru
Cite this article as: Minchev A., Korzhenkov A.M., Ovsyuchenko A.N., Dimitrov O.V., Larkov A.S., Ranguelov B.K., Rogozhin E.A., Andreeva N.V. Deformations in episcopal basilica in Varna – evidences of the strong historical earthquakes in North-Western Bulgaria, Geofizicheskie Protsessy i Biosfera (Geophysical Processes and Biosphere), 2020, vol. 19, no. 3, pp. 16–32 (in Russian). https://doi.org/10.21455/gpb2020.3-2
English version: Izvestiya, Atmospheric and Oceanic Physics, 2020, vol. 56, iss. 10. ISSN: 0001-4338 (Print), 1555-628X (Online). https://link.springer.com/journal/volumesAndIssues/11485