2 Institute of Geophysical Research of Ministry of Energy of Republic Kazakhstan, Almaty, Kazakhstan
Abstract. We have been studying some seismicity characteristics in the region of the Northern Balkans. We used method based on identifying ring-shaped seismicity structures which are forming often prior to large earthquakes in continental regions. Relatively large shallow (h = 0–33 km) ring-shaped structures were identified within two areas, where no relatively large earthquakes (М ≥ 6.5) have occurred since 1900. Meridional structure with threshold magnitude value Mt = 4.2 and big axis length L ≈ 150 km has been formed within the west area, bounded by coordinates of 42.0–44.5° N and 15.5–17.5° Е. The larger structure (Мt = 4.1, L ≈ 180 km) revealed within the east area (41.0–43.5° N and 21.5–23.5° Е). Besides of shallow rings, deep seismicity strips (h = 34–70 km) have been formed within the both areas. Magnitudes of possible large events were estimated on the base of earlier obtained correlation dependences of seismicity ring parameters on energy of main earthquakes with different mechanisms: Mw = 7.2±0.2 и Mw = 6.7±0.1 for the west and east areas correspondingly. By analogy with some continental regions, first of all Greece, we suppose that epicenters of possible large earthquakes can be located near crossing sections of the shallow rings and deep seismicity strips. A conclusion was drawn that in the near years large event is most probable within the east area.
Keywords: Northern Balkans, large earthquakes, ring-shaped seismicity structures.
KOPNICHEV Yuri F. – dr. of ph. & math., professor, chief research scientist, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences. Moscow, Russia. Tel.: +7 (7272) 956-350. E-mail: yufk777@mail.ru.
SOKOLOVA Inna N. – dr. of ph. & math., senior scientist, Institute of Geophysical Research of Ministry of Energy of Republic Kazakhstan. Almaty, Kazakhstan. Tel.: +7 (7272) 631-330. E-mail: sokolova.inessa@mail.ru.
Cite this article as: Kopnichev Yu.F., Sokolova I.N. Ring-shaped seismicity structures in the region of the Northern Balkans: Possible preparation for large earthquakes, Voprosy Inzhenernoi Seismologii (Problems of Engineering Seismology), 2018, Vol. 45, No. 1, pp. 31–38. [in Russian]. DOI: 10.21455/VIS2018.1-3
English translation of the article will be published in Seismic Instruments, ISSN: 0747-9239 (Print) 1934-7871 (Online), https://link.springer.com/journal/11990), 2019, Volume 55, Issue 1.