Bedrock landslide; dendrogeomorphology; landslide recurrence; electrical resistivity tomography; meteorological triggers; Flysch Carpathians

Landslides predisposed by the anisotropy of flysch bedrock are typical features of mass movements affecting the Outer Western Carpathians. A dendrogeomorphic investigation involving an extensive dendrometric (n=1680) survey and tree-ring analysis of 176 Norway spruce trees (Picea abies (L.) Karst.) was used to reconstruct the spatial and temporal activity of the Mazák landslide, situated in the highest part of the Czech Outer Western Carpathians. As revealed by geomorphic analysis and electrical resistivity tomography, the landslide is a translational medium-depth (<30 m) bedrock feature originating at the intersection of inclined bedding planes with diagonal (NW-NNW striking) and longitudinal (NE striking) sets of joints and faults. A tree-ring analysis shows nine major landslide years (1929, 1940, 1949, 1960, 1972, 1980, 1985, 1997, 2000) accompanied by six additional years with minor reactivations (1933, 1945, 1955, 1958, 1977, 1996) during the past hundred years (1912-2011).