Last night (22:29 UTC on 22 April) a M4.5 earthquake rattled NE Hungary. The event was shallow (~10 km) and the epicentre was only about 25 km south of the city of Eger, famous for its red wine (Egri bikavér). The area is south to the Inner Western Carpathian Mountains. Light damage has been reported from the epicentral area, the EMSC questionnaires document intensities of VI.
Felt reports (Data source: EMSC)
USGS data suggest a compressional focal mechanism. I thought orogeny in the Carpathian Mountains would have been finished in Tertiary early Neogene… The website http://www.seismology.hu provides more information on recent earthquakes in Hungary.
EMSC seismicity data illustrate that this area is not really known for its seismic activity:
Seismicity 1960-today. Source: EMSC
Seismic hazard in this region is among the lowest in the country, see http://www.seismology.hu/index.php/en/seismicity.
Seismic hazard in Hungary. Source: USGS
The Archive of Historic Earthquake Data (AHEAD) lists a magnitude 6 event on 15 October 1834 as strongest earthquake in historical times in E Hungary (intensities ~IX), and another event of magnitude 6.2 occurred in 1763 close to the Hungary-Slovakia border. In 1561, a moderate event rattled Budapest and in 1868 another moderate earthquake occurred near Eger.
So, although some strong historic events are known for Hungary, the area of yesterday’s earthquake wasn’t really thought to be active – no really important events happened there during the last 1000 years. Or maybe it’s only no events that we know of. Bad luck for the people that need to repair their houses now. Good luck there has been only minor damage…
References and further reading:
- Bodri, B., 1996. Thermal state, rheology and seismicity in the Pannonian Basin, Hungary. Journal of Geodynamics, 21 (4), 309-328.
- Bus, Z., Szeidovitz, G., Vaccari, F., 2000. Synthetic Seismogram Based Deterministic Seismic Zoning for the Hungarian Part of the Pannonian Basin.
- Szeidovitz, G., Surányi, G., Gribovszki, K., Bus, Z., Leél-Ossy, S., Varga, S., 2008.
Estimation of an upper limit on prehistoric peak ground acceleration using the parameters of intact speleothems in Hungarian caves. J Seismol, 12, 21-33.
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Zsíros, T., 2006. Érmellék seismic source zone. Acta Geodaetica et Geophysica Hungarica 41 (2), 237-247.
José A. Alvarez-Gómez | 2013-04-24|14:42 (UTC)
Maybe you can find of interest the model of topography-induced stresses of Bada et al. (2001) for the area. Their results are in agreement with the compressive focal mechanism of the USGS.
Bada, G., Horváth, F., Cloething, S., Coblentz, D.D. and Toth, T. (2001) Role of topography-induced gravitational stresses in basin inversion: The case study of the Pannonian basin, Tectonics, 20(3): 343-363.