Seismogeological pattern of a transition area between the Eastern Alps and the Western Carpathians

Abstract

All available seismological data (earthquake epicentres, macroseismic observations) and the available structural-tectonical, geomorphological and geodetic data for the transition area of two fundamental orogenetic units of Central Europe -the Eastern Alps and the Western Carpathians -are analyzed, with the aim to find seismogenic zones of this area and to assess their possible earthquake activity. The relationship of small local geological structures to the fundamental European tectonic blocks is discussed from the viewpoint of seismotectonic processes expected for the transition area, especially in the Vienna Basin and in the Little Carpathians. The special attention is paid to the densely inhabited area of the city of Bratislava which is situated in the territory under study. Some results could contribute to its further urban planning. On several faults or boundaries in the Western Carpathians relatively intense horizontal displacements have been observed. Fundamental movements on faults of NS to NE-SW directions have mostly sinistral character while on some faults of ENE-WSW direction they are dextral. In the southern parts of the investigated area, dextral movements on local faults of NW-SE direction have been found. A neotectonic model of the broader surroundings of the city of Bratislava is presented.