dendrogeomorphology; chronology; tree-rings; landslide

Drobné svahové pohyby často předchází vzniku mnoha současných katastrofických sesuvů. Je také časté, že po velkých sesuvných událostech následuje série menších pohybů.

Minor slope movements often precede the origin of many recent catastrophic landslides. It is also common, that large landslide events are followed by sequence of minor movements. Thus, information about minor movements preceding the landslide is very important for potential landslide hazard and risk assessment, but data showing the pre-landslide activity are very scarce (if any). Dendrogeomorphic methods bring good results in the recognition of the slope activity sequences. In our study, the pre- and post-catastrophic Ľubietová landslide activity was studied. The Ľubietová landslide is 1200 m long and approximately 10-20 m deep. Catastrophic reactivation of the landslide occurred during February 1977. In the area of 1977 source zone and in the position of old landslide blocks lying above the 1977 reactivation, trees with clearly visible signs of past landslide activity (with tilted or bended stems) were sampled by Pressler increment borer.