Slovakia hit by the strongest earthquake since 1930
On the evening of Monday, October 9, 2023, eastern Slovakia was hit by a moderately strong earthquake, which caused several damages to property. The scientific team of the Earth Science Institute of the SAS has been mapping the situation from the first moments and offering the first interpretations of seismic records.
Monday's earthquake at 20:23:10 CET (18:23:10 UTC), with the epicenter in the cadastre of the village of Ďapalovce (district Vranov nad Topľou) had a local magnitude of Ml 4.9 after manual refinement. The epicenter was only 1.3 km from the center of the village of Ďapalovce, 22 km from the district town of Vranov nad Topľou and 19.5 km from Humenné.
"The first estimates of the depth of the hypocenter, which range from 4-18 km, should be considered preliminary. They can be made more precise only by a detailed analysis of seismic records, especially from nearby seismic stations," explains Peter Moczo from the Earth Science Institute of the SAS and the Faculty of Mathematics, Physics and Informatics of the Comenius University.
According to information from Ďapalovce and the surrounding villages, material damage has been reported to the buildings, even on a large scale, with structural damage or destruction of the load-bearing walls of the buildings. The damage depends on the type, quality of the construction and also the geological composition of the subsoil at the construction site.
"Citizens send completed macroseismic questionnaires, which are available on the website https://www.seismology.sk/. By 11. 10. 2023, 12:16 p.m. 1,942 reports were received and processed from 461 locations, mainly from the territory of eastern Slovakia, but also from central and occasionally from western Slovakia, up to a distance of min. 200 km from the epicenter, which is more than one verified observation," states Ján Madarás, Director of the Earth Science Institute of the SAS.
Questionnaires and damage documentation are an essential basis for determining the degrees of macroseismic intensity (I°) according to the European macroseismic scale EMS-98, which will also serve insurance companies when assessing damage events in areas above I° = 6°. Given the size of the earthquake, macroseismic effects can be expected to reach level 7 in some built-up areas from the 12-level European macroseismic scale EMS-98.
Due to the scale of the earthquake, the Institute deployed three teams of experts directly in the field. "Our researchers collect and analyze data from temporarily located seismometers and document the observed effects of the earthquake. We will continue to update and refine the information based on field findings," adds J. Madarás.
From a historical perspective on the size of the earthquake, Monday's earthquake ranks among the 15 to 20 largest earthquakes in our territory since 1443. Within eastern Slovakia, this is the strongest earthquake since 1914 (Giraltovce and the surrounding area) and, compared to the whole of Slovakia, the strongest earthquake since 1930 (the area of Dobrá Voda in the north of the Small Carpathians).
Overview of earthquakes in the vicinity of Humenné and Vranov nad Topľou
The sequence of earthquakes in 1778-1779
19.12.1778 I0 = 7° EMS-98 Mw » 5,0 h = 12 km
23.12.1778 I0 = 7° EMS-98 Mw » 4,8
6.4.1779 I0 = 7° EMS-98 Mw » 4,8
damage in Strážske, Vranov nad Topľou, Michalovce and Humenné (and the surrounding areas of these places)
destroyed, e.g., manor house in Tovarné, rectory in Matiašovce [Ondavské Matiašovce? / Matiaška?], Roman Catholic church in Strážske
Earthquakes in the second half of the 19th century
17.8.1885 I0 = 6° EMS-98 Mw » 4,3
the greatest damage in Vranov nad Topľou (cracked chimneys), damaged mansion in Tovarné
28.12.1890 I0 = 6-7° EMS-98 Mw » 4,6 h = 10 km
the greatest damage in Humenné, Strážske, Nižný Hrabovec and Topoľovka (cracked buildings)
15.4.1893 I0 = 6-7° EMS-98 Mw » 4,5 h = 9 km
the greatest damage in Stropkov and the village of Varechovce (the epicenter was east of Stropkov)
in the village of Varechovce, cracks appeared in the walls, the wall of one barn with a length of 2 m collapsed
in Stropkov, cracks appeared on the buildings, several chimneys fell
Earthquakes in the 20th century
26.5.1914 I0 = 7° EMS-98 Mw » 4,8
the greatest damage in Giraltovce and Hanušovce nad Topľou
several buildings were damaged in the village of Dobrá, chimneys collapsed in Giraltovce, a church cracked in Hanušovce, several buildings were damaged in Humenné and Vranov
18.2.1932 I0 = 5-6° EMS-98 Mw » 4,1 h = 9 km
damage in the town of Humenné and in the villages of Brekov and Petrovce nad Laborcom
5.6.1941 I0 = 7° EMS-98 Mw » 4,4
the greatest damage in Strážske (cracked walls, damaged tall chimney, damaged Greek Catholic church in Strážske) and Humenné
The strongest earthquake in the 21st century (area below Vihorlat)
20.5.2003 I0 = 6-7° EMS-98 Mw = 4,3 h = 3,7 km
the greatest damage in the villages of Jasenov (Sobrance district) and Baškovce
Source: Ján Madarás, Róbert Kysel, Peter Moczo, Kristián Csicsay, Lucia Fojtíková, Peter Pažák, František Šipka, Earth Science Institute of the SAS, Faculty of Mathematics, Physics and Informatics of the Comenius University, EQUIS, s r. o.
Prepared by: Katarína Gáliková
Photo: TASR and Earth Science Institute of the SAS