Kinematics, seismotectonics and seismic potential of the eastern sector of the European Alps from GPS and seismic deformation data

Fragmentation of the Adriatic Promontory: New Chronological Constraints From Neogene Shortening Rates Across the Southern Alps (NE Italy)

“…Our results suggest that NNE‐SSW oriented shortening at a rate of 1.5 ± 0.3 mm/year since the LGM period has led to folding of alluvial markers of the Veneto‐Friuli plain. This value is in agreement with geodetic profiles across the belt (Cheloni et al, ; Serpelloni et al, ) and suggests that about 75% of Adria‐imposed convergence is absorbed across the eastern Southern Alps. While it appears that slip is equally shared between the main Tricesimo thrust (15.7 ± 1.3 m) and the Udine thrust splays (11.6 ± 1.6 m) over the last 15–18 ka, the balanced cross section shows that the total slip transferred to the Udine thrust splay is very low compared to the entire structure (900–1,200 m versus about 12 km; see Figure ) suggesting the Udine thrust splay has been recently activated.…”

“…Moreover, no surface faulting can be detected NNE of Trevise along the southern branch (Figures and ; that one could expect to parallel the NE‐SW striking section of the northern branch) suggesting again a lower uplift above the NE‐SW striking section of the thrust. This is further confirmed by geodetic data, which show that a lower rate of shortening as well as a 1 mm/year left‐lateral component is accommodated across the NE‐SW oriented section (Maniago segment and northeastern part of the Montello segment) of the frontal thrust zone (Serpelloni et al, ). Moreover, left‐lateral motion along this section of the belt agrees with the distribution of fault‐plane solutions during the 3 years that followed the 1976 main shock of the Friuli sequence: specifically, sinistral focal mechanisms (M L from 3.4 to 4.5) were found to align in a NE‐SW trend parallel to the NE‐SW section of the Piave river (Slejko et al, ).…”

“…Specifically, there is a bend in the thrusts geometry from E‐W (in the east) to NE‐SW orientation (in the west) well seen about 15 km west of Tolmezzo (Figure ). This change in orientation correlates with the western tip of the Fella‐Sava back thrust (Figure ) for which a right‐lateral component of about 1 mm/year has been inferred from geodetic data (Serpelloni et al, ). We thus interpret the bent geometry of the thrusts as suggesting that the long‐term deformation across the eastern part of the eastern Southern Alps has been partitioned between SSW thrusting and E‐W oriented right‐lateral motion, allowing accommodation of a general NW‐SE convergence at the scale of the entire belt (Castellarin & Cantelli, ; Schönborn, ), in agreement with microtectonic analyses (Caputo et al, ).…”

“…Inception of slip on the Montello thrust is thought to have occurred in the Pleistocene (Benedetti et al, ; Caputo et al, ), similar to the Udine thrust splays. Such a young activation could be consistently related to the fact that the Maniago thrust has the strongest large‐scale geomorphic expression (Figure ) despite the significantly lower shortening rate it absorbs (Serpelloni et al, ). On the other hand, microtectonic analyses documented a shift in the direction of maximum compression from N314 during the Pliocene to N340 during the Pleistocene (Caputo et al, ).…”

First evidence of active transpressive surface faulting at the front of the eastern Southern Alps, northeastern Italy: insight on the 1511 earthquake seismotectonics

“…8). Ultimately, this study raises significant issues on a potential major seismogenic source of a region where interseismic coupling suggests elastic strain is building up at seismogenic depths which will be released in future large earthquakes (Cheloni et al, 2014;Serpelloni et al, 2016).…”