We describe here the results of the characterization of subsurface structures in an area of the south-eastern edge of the Bohemian Massif, in Austria by high-resolution geophysical survey techniques and advanced analysis methods of potential fields. The employed methods included potential field multiscale techniques for source-edge location and characterization of sources at depth. Our results confirmed the presence of already known structures: the location of the Diendorf Fault and the Moldanubian Shearzone are clearly recognized in the data at the same location as on the geological maps, even where the Diendorf fault is covered with sediments of the Molasse Basin. In addition, we detected several geological contacts between different rock types in the Bohemian Massif west of the Diendorf Fault. From our results, we were also able to quickly identify and image, without a priori information, previously unknown structures, such as faults with-depth-to-the top of about 500 m and magmatic intrusions about 400 m deep.
Owing to the low N‐S convergence rates between Adria and Europe, crustal deformation rates in the Alps and its forelands are low. Active tectonics are, therefore, difficult to study, especially as non‐tectonic landscape forming processes can erase or modify the tectonic surface imprint. Large‐scale and dense seismological data recently offered insights into earthquakes and into the lithospheric structure beneath the Alps. Recent field studies added data on geological archives of active tectonics. In this review, we summarize the results from studies of seismic tomography, geodesy, seismology, historical seismology, archeoseismology, on‐fault and off‐fault paleoseismology, and fault gouge dating, focusing on the eastern part of the Alps during the last c. 1 Ma. We discuss the influence of the lithosphere on the localization of deformation, and we draw a generalized picture of active deformation. We show that deformation is primarily accommodated across the South Alpine Front (∼2 mm/yr out of max 3 mm/yr total shortening) and NW‐SE striking strike‐slip faults in western Slovenia (∼1.5 mm/yr shear). Large fault systems in the interior of the Eastern Alps are still actively accommodating extrusion of crustal material toward the east at very low rates (0.5–1.0 mm/yr). Diffuse deformation and clusters of seismicity are observed in the interior of the Alps. Minor shortening occurs at the North Alpine Front. Crustal strength controls the localization of deformation resulting in non‐deforming blocks. Neogene slab break‐off events do not control the present‐day deformation. Instead, present‐day uplift of 1.5–2 mm/yr correlates to areas glaciated during the Last Glacial Maximum.
The reuse of vintage datasets which were acquired in the 20th century can pose challenges for modern geophysical modeling due to missing detailed preprocessing information, significant uncertainties, or lack of precise tracking, etc. Nevertheless, they are often the only available datasets in a target region. We explore here the potential of such vintage airborne geophysical datasets (magnetics, AEM, radiometrics) to detect the location and dip direction of geological faults, using a non-modeling interpretation approach based on multiple GIS tools. We apply our approach in a geologically well-known region where four different types of faults are mapped. The applicability of the tools used in this study depend on the geological setting of each fault and is evaluated based on the comparison with geological and—where available—with modeling data. In general, the GIS tools, especially used on a combination of datasets, show reliable results concerning the location and strike of faults, and even seem to be able to predict the dip direction of a fault.
Owing to the low N-S convergence rates between Adria and Europe, crustal deformation rates in the Alps and its forelands are low. Active tectonics are, therefore, difficult to study, especially as non-tectonic landscape forming processes can erase or modify the tectonic surface imprint. Large-scale and dense seismological data recently offered insights into earthquakes and into the lithospheric structure beneath the Alps. Recent field studies added data on geological archives of active tectonics. In this review, we summarize the results from studies of seismic tomography, geodesy, seismology, historical seismology, archeoseismology, on-fault and off-fault paleoseismology, and fault gouge dating, focussing on the eastern part of the Alps during the last c. 1 Ma. We discuss the influence of the lithosphere on the localization of deformation, and we draw a generalized picture of active deformation. We show that deformation is primarily accommodated across the South Alpine Front (~2 mm/yr out of max 3 mm/yr total shortening) and NW-SE striking strike-slip faults in western Slovenia (~1.5 mm/yr shear). Large fault systems in the interior of the Eastern Alps are still actively accommodating extrusion of crustal material towards the east at very low rates (0.5-1.0 mm/yr). Diffuse deformation and clusters of seismicity are observed in the interior of the Alps. Minor shortening occurs at the North Alpine Front. Crustal strength controls the localization of deformation resulting in non-deforming blocks. Neogene slab break-off events do not control the present-day deformation. Instead, present-day isostatic uplift of 1.5-2 mm/yr correlates to areas glaciated during the Last Glacial Maximum.