No abstract

We present the compilation of a new database of active faults in Slovenia, aiming at introducing geological data for the first time as input for a new national seismic hazard model. The area at the junction of the Alps, the Dinarides, and the Pannonian Basin is moderately seismically active. About a dozen Mw > 5.5 earthquakes have occurred across the national territory in the last millennium, four of which in the instrumental era. The relative paucity of major earthquakes and low to moderate fault slip rates necessitate the use of geologic input for a more representative assessment of seismic hazard. Active fault identification is complicated by complex regional structural setting due to overprinting of different tectonic phases. Additionally, overall high rates of erosion, denudation and slope mass movement processes with rates up to several orders of magnitude larger than fault slip rates obscure the surface definition of faults and traces of activity, making fault parametrization difficult. The presented database includes active, probably active and potentially active faults with trace lengths >5 km, systematically compiled and cataloged from a vast and highly heterogeneous dataset. Input data was mined from published papers, reports, studies, maps, unpublished reports and data from the Geological Survey of Slovenia archives and dedicated studies. All faults in the database are fully parametrized with spatial, geometric, kinematic and activity data with parameter descriptors including data origin and data quality for full traceability of input data. The input dataset was compiled through an extended questionnaire and a set of criteria into a homogenous database. The final database includes 96 faults with 240 segments and is optimized for maximum compatibility with other current maps of active faults at national and EU levels. It is by far the most detailed and advanced map of active faults in Slovenia.

No abstract

In Slovenia, mass movements are not only a threat to the population, but also a major environmental and social science challenge. Lithologically heterogeneous areas have been found to be problematic, and the Miocene Slovenj Gradec basin (in northeast Slovenia) is one such area. For this area, we developed landslide and rockfall susceptibility maps based on detailed geological research combined with statistical modeling schemes. Crucial factors include lithological composition, land use, geological structural elements, slope curvature, aspect and inclination, and bed dipping. The approach taken in the development of mass movement susceptibility maps presented here is transferable to other areas defined by heterogeneous lithology. Such maps could prove useful spatial planning, forestry, environmental protection, landscape architecture, and other fields.

Seismic hazard assessment requires seismic source models representative for time spans greater than the period of earthquake catalogue completeness. In order to include seismic deformation in a several hundreds to thousands of year time interval, we need to rely on long-term geologic input in the form of fault seismogenic sources. This is particularly valid for low to moderate seismic deformation rate areas, where strong earthquakes tend to have long return periods, as is the case in Slovenia.