Modellizzazione numerica di zone di taglio viscoso: instabilità periodiche connesse ai terremoti intermedi-profondi

Numerical study of a periodic re-activation of a shear zone in a subduction framework, involving a shear-heating mechanism. We developed a 1D model, encompassing the shear zone and the wall-rock in order to control strain rate, temperature, stress and grain size parametersope

Late quaternary tectonic activity of the Udine-Buttrio Thrust, Friulian Plain, NE Italy

The NW-SE trending Udine-Buttrio Thrust is a partly blind fault that affects the Friulian plain southeast of Udine in NE Italy. It is part of a wider fault system that accommodates the northward motion of the Adriatic plate. Although seismic reflection data and morphological evidence show that the fault was active during the Quaternary, comparably little is known about its tectonic activity. We used high-resolution digital elevation models to investigate the surface expression of the fault. Measured vertical surface offsets show significant changes along strike with uplift rates varying between 0 and 0.5 mm/yr. We then analyze a topographic scarp near the village of Manzano in more detail. Field mapping and geophysical prospections (Georadar and Electrical Resistivity Tomography) were used to image the subsurface geometry of the fault. We found vertical offsets of 1–3 m in Natisone River terraces younger than 20 ka. The geophysical data allowed the identification of deformation of the fluvial sediments, supporting the idea that the topographic scarp is a tectonic feature and that the terraces have been uplifted systematically over time. Our findings fit the long-term behaviour of the Udine-Buttrio Thrust. We estimate a post-glacial vertical uplift rate of 0.08–0.17 mm/yr recorded by the offset terraces. Our results shed light on the Late Quaternary behaviour of this thrust fault in the complicated regional tectonic setting and inform about its hitherto overlooked possible seismic hazard

Modellizzazione numerica di zone di taglio viscoso: instabilità periodiche connesse ai terremoti intermedi-profondi

Numerical study of a periodic re-activation of a shear zone in a subduction framework, involving a shear-heating mechanism. We developed a 1D model, encompassing the shear zone and the wall-rock in order to control strain rate, temperature, stress and grain size parameter

An advertising game with multiplicative interference

Two competing manufacturers provide a homogeneous market with substitutable products and want to maximize their profits. Each firm may advertise its brand, with a positive effect on its own brand and negative on the competitor\u2019s one. Moreover, each firm may choose an advertising medium to use among several available media. We assume that the advertising effect on demand is mediated by the goodwill variable and that a competitor\u2019s interference may be represented as a proportional reduction of the virtual goodwill. We model the manufacturers\u2019 problem as a noncooperative game under complete information and discuss the existence and features of its Nash equilibria

Late Quaternary Tectonic Activity of the Udine-Buttrio Thrust, Friulian Plain, NE Italy

The NW-SE trending Udine-Buttrio Thrust is a partly blind fault that affects the Friulian plain southeast of Udine in NE Italy. It is part of a wider fault system that accommodates the northward motion of the Adriatic plate. Although seismic reflection data and morphological evidence show that the fault was active during the Quaternary, comparably little is known about its tectonic activity. We used high-resolution digital elevation models to investigate the surface expression of the fault. Measured vertical surface offsets show significant changes along strike with uplift rates varying between 0 and 0.5 mm/yr. We then analyze a topographic scarp near the village of Manzano in more detail. Field mapping and geophysical prospections (Georadar and Electrical Resistivity Tomography) were used to image the subsurface geometry of the fault. We found vertical offsets of 1–3 m in Natisone River terraces younger than 20 ka. The geophysical data allowed the identification of deformation of the fluvial sediments, supporting the idea that the topographic scarp is a tectonic feature and that the terraces have been uplifted systematically over time. Our findings fit the long-term behaviour of the Udine-Buttrio Thrust. We estimate a post-glacial vertical uplift rate of 0.08–0.17 mm/yr recorded by the offset terraces. Our results shed light on the Late Quaternary behaviour of this thrust fault in the complicated regional tectonic setting and inform about its hitherto overlooked possible seismic hazard

Geophysical survey (GPR, ERT, magnetic) on active faults in Slovenia and Italy

The transition zone between the Southern Eastern Alps and the Dinarides is situated in western Slovenia and northeastern Italy. Here, a system of mainly NW-SE trending, right-lateral strike-slip faults accommodates the shortening between the Adriatic Plate and Eurasia. Due to the low deformation rates, geodetic techniques and seismology provide only limited insights into the activity of those faults. Geomorphological studies are confronted with problems arising from the low fault slip rates, distributed deformation, and unfavourable conditions due to the karst environment. One way to overcome these problems is the use of paleoseismology, i.e. the excavation of active faults to study their earthquake history and slip behaviour. A prerequisite for paleoseismological trenching is knowledge on the precise location of the fault trace and the availability of a suitable sediment record. We performed geophysical surveys across the potentially active faults in Slovenia and Italy to select sites for paleoseismic trenching. We used a ground-penetrating radar (GPR) system from Geophysical Survey Systems Inc (GSSI) with monostatic 100 MHz, 270 MHz, and 400 MHz antennas and a Pulse EKKO Pro Sensors & Software system equipped with bistatic 250 MHz antennas. All data were processed with the ReflexW software (Sandmeier Geophysical Research). Processing included frequency bandpass filtering, background removal, gain adjustments, and topographic corrections. The topographic data were extracted from the 1 m DEM. Electric resistivity tomography (ERT) was performed with a 4-point-light system (Lippmann Geophysikalische Messgeräte). We used up to 80 electrodes with varying electrode spacing for Wenner, Schlumberger, and Dipole-Dipole arrays, depending on target resolution and depth. Data inversion was done with Res2DInv (Geotomo Software) and included manual de-spiking and topographic corrections. Along several profiles we measured the vertical gradient of the geomagnetic field and the total magnetic field strength with a proton magnetometer GSM - 19T (GEM Systems). The system consists of a rover and a base station, which allows correcting the data for diurnal variation. Depending on the equipment used and the survey parameters, these methods allow insights into the first few metres of the subsurface with a resolution of few centimetres (georadar) to a few metres (ERT). We focussed on sites that host Quaternary sediments. Most of the data in this dataset are 2D profiles perpendicular to the mapped traces of active faults. Several promising sites were investigated in 2.5D, i.e. the profile line spacing was dense enough to compute a pseudo-3D dataset. We collected the data in May and June, 2018. This dataset contains ~2.5 km of magnetic data, ~20 km of GPR data, and ~1.7 km of ERT data. This work was undertaken for the DFG project "Earth surface response to Quaternary faulting and shallow crustal structure in the eastern Adria-Alpine collision zone and the Friulian plain" within the DFG-funded priority programme SPP2017 - Mountain building processes in 4D