Indicators for earthquake-induced soil slides in the flatlands of an Alpine Fringe area

Abstract

In Austria’s most eastern province Burgenland, an ongoing study of the regional distribution of mass movements has been performed. In this alpine fringe area more than 280 previously unrecognized active mass movements were mapped, most of them are identified as creep or soil slides. We assume that the majority of these landslides were triggered by intense rainfall, but we also found strong indications that at least two large scale movements might be earthquake-induced. These two movements, each covering an area of more than 1 km2, are situated in the north of the province. In other parts of the province the dimension of mapped landslides averages only 0.03 km2. Compared to the other areas, the hill slopes in the north have the lowest steepness and the lowest annual precipitation. Underground geologic conditions, however, are overall comparable. Earthquakes are only documented in the north of the province and they could have acted as additional trigger for these comparatively large scale landslides with their noticeable different pattern in dimension and volume.