Seismic activity and neotectonic evolution of theWestern Carpathians (Slovakia)

Abstract

Abstract. Seismic activity in the Western Carpathians is closely related to the crustal rheology and combined structural pattern within the brittle upper crust. The structural pattern is a combination of three structural levels. The deepest level is represented by the Paleo-Alpine suture zones dissected by neo-Alpine fault structures, above all strikeslip fault zones (second level). The recent tectonic regimes are controlled by the contemporary stress field and vertical movements (third level). Following the analyses of structures and various geophysical data, the principal seismo-tectonic zones of the Western Carpathians are defined.The most remarkable and important first-order tectonic structure in the Western Carpathians is the zone of the Pieniny Klippen Belt, which represents the contact of the Western Carpathian internides and the stable European Platform.The Mur-Mürz-Leitha fault zone in the area of the Vienna Basin represents the contact of the Eastern Alps with the block of Western Carpathian internides. Both these tectonic lines represent subvertical boundaries with Tertiary tectonic activity.TheČertovica fault zone is a surface projection of the thrust plane of the Veporic thick-skinned sheet over the Tatric unit. Based on geological and geophysical data it is assumed that theČertovica zone is recently active due to its extensional reactivation. Earthquake events are released here mostly along the Hron fault system of the ENE-WSW direction.The next important tectonic structure is the HurbanovoDiósjenő line, which is most probably the continuation of the Rába line into the Slovak territory. Based on reflection seismic interpretations, there are several low-angle fault surfaces dipping to the SE. These thrust planes were reactivated durCorrespondence to: M. Kováč (kovacm@nic.fns.uniba.sk) ing the Miocene as low-angle extensional faults. The seismic events (e.g. Komárno area) are most probably generated on these low-angle surfaces.

The Use of a Karstic Cave System in a Study of Active Tectonics: Fault Movements Recorded at Driny Cave, Malé Karpaty M (Slovakia)

“…The NW-SE striking fault in 'Collaborators' Passage' (Driny 3) has displayed subsidence of the northeastern block by 0.03 mm/yr and dextral strike-slip displacement trend of 0.04 mm/yr (Fig. 10) The dextral strike-slip results are in full accordance with previous geological ideas regarding the mechanism of the transverse Malé Karpaty strike-slip fault displacements (Kováč et al, 2002). In addition, the observed sense of displacement reflects a continuation of the horizontal dextral shift previously noted on slickensides in the Collaborators' Passage.…”

“…The sense of regional 2D deformation ellipse model is derived from McClay (1987). The sinistral strike-slip displacements are consistent with the interpreted displacement mechanism along the Smolenice Fault, in addition to the other NE-SW and N-S striking faults in the Malé Karpaty Mts (Kováč et al, 2002).…”

“…The latter transverse fault system is thought to be responsible for dividing the main ridge of the Malé Karpaty Mts into a series of discrete morphostructural blocks during the Quaternary. It has recently been determined that movement on these NW-SE striking faults are dextral strike-slip (Kováč et al, 2002).…”

The Šariš Transitional Zone, revealing interactions between Pieniny Klippen Belt, Outer Carpathians and European platform

“…The Dunajec Fault and parallel Poprad Fault have also experienced recent seismic activity (Wiejacz 1994;Guterch et al 2005). There is a linear (NNW-SSE-oriented) string of earthquake epicenters, extending from Krościenko in Poland up to the east of Spišská Nová Ves in Slovakia (Kováč et al 2002). The strike-slip activity of NNW-SSE-oriented faults could be connected with N to NNE-oriented vectors of recent horizontal motions, observed for seismic stations located south of the Pieniny Klippen Belt, pointing to the ongoing NNE-directed push of the Alcapa block (Jarosiński 1998(Jarosiński , 2005Łój et al 2009).…”

Studies of Historical Earthquakes in Southern Poland

“…The most seismically active in the Western Carpathians are the regions of Žilina, Dobrá Voda (the best spatially defined focal zone), Malé Karpaty Mts, Central Slovakia, Komárno and Slanské Vrchy Mts (Slovakia). The three largest earthquakes were those of 5 June 1443 in Central Slovakia, 28 June 1763 in Komárno and 9 January 1906 in Dobrá Voda, all with epicentral intensity I o = 8-9 (MKS) (Kováč et al 2002). Earthquakes from Žilina have been known since the XVII century, where the strongest event was that of 16 November 1613 with I o = 8 (Labák and Brouček 1996), causing damage to buildings in Bratislava.…”