Abstract. We investigated the eastern corner of northeastern Italy, where a system of NW–SE-trending dextral strike-slip faults of western Slovenia intersects the south-verging fold and thrust belt of the eastern Southern Alps. The area suffered the largest earthquakes of the region, among which are the 1511 (Mw 6.3) event and the two major shocks of the 1976 seismic sequence, with Mw = 6.4 and 6.1. The Colle Villano thrust and the Borgo Faris–Cividale strike-slip fault have been here first analyzed by interpreting industrial seismic lines and then by performing morphotectonic and paleoseismological analyses. These different datasets indicate that the two structures define an active, coherent transpressive fault system that was activated twice in the past two millennia, with the last event occurring around the 15th–17th century. The chronological information and the location of the investigated fault system suggest its activation during the 1511 earthquake.

To cope with the general reduction of water availability and increase the subsurface storage of high-quality surficial waters, an artificial recharge project is ongoing in northern Italy within the WARBO LIFE+ Project funded by EU. WARBO is aimed at implementing large-scale use of artificial recharge in Italy where water directives still strongly limit its application. In this context, the Mereto recharge site was selected in the upper Fruili plain where the water availability is guaranteed during winter period by the Tagliamento and Ledra Rivers. An infiltration basin, about 5.5 m deep and 45 × 7 m2 wide, was built at Mereto in the early 2000s but the possibility of implementing the recharge has been allowed only very recently. The site is characterized by an elevation of 105 m asl and the depth to the groundwater table averages 50 m. Below a few meter-thick organic soil, the aquifer is composed by coarse deposits with an estimated thickness of 100 m and an average vertical hydraulic conductivity on the order of 10−4 m/s. A ~0.1 m3/s infiltration flow has been preliminary estimated (corresponding to an infiltration rate of 60 cm/h). Geophysical investigations (electrical resistivity tomography, high-resolution seismic surveys) together with infiltration and pumping tests have been carried out to characterize the vadose zone and the unconfined aquifer in the study area. Functional approaches and three-dimensional (3D) Finite Element numerical computations have been used to predict the effect of the artificial recharge. The results of these investigations will greatly reduce the hydrogeological knowledge gaps and will be used to fine tune the recharge program and to define the monitoring concept. This contribution aims to provide a methodology for the implementation of managed aquifer recharge programs using existing structure

Abstract. We investigated the eastern corner of northeastern Italy, where the NW-SE trending dextral strike-slip fault systems of western Slovenia intersects the south-verging fold and thrust belt of the eastern Southern Alps . The area suffered the largest earthquakes of the region, among which are the 1511 (Mw 6.3) event and the two major shocks of the 1976 seismic sequence, with Mw = 6.4 and 6.1 respectively. The Colle Villano thrust and the Borgo Faris-Cividale strike-slip fault have been first analyzed by interpreting industrial seismic lines and then by performing morpho-tectonic and paleoseismological analyses. These different datasets indicate that the two structures define an active, coherent transpressive fault system that activated twice in the past two millennia, with the last event occurring around the 15th–17th century. The chronological information, and the location of the investigated fault system suggest its activation during the 1511 earthquake.

No abstract

Unit 2: colluvial deposit made of yellowish/brownish sandy silt with sparse cm-size polygenic pebbles and charcoals fragments. Interpretazione stratigrafiche nel unità poligeniche tagliamento Unit 3: colluvial deposit made of brownish massive sandy silt containing cm-size polygenic pebbles (mostly organised in gravel lenses), charcoal fragments and Fe-Mn concretions. Unit 4: alluvial deposit made of clast-supported gravel with brownish silty matrix. Unit 5: colluvial deposit made of massive yellowish-brownish sandy silt containing cm-size polygenic pebbles (mostly organised in gravel lenses), charcoal fragments and Fe-Mn concretions Unit 6: colluvial deposit made of yellowish and locally brownish clayey silt with sparse clasts (10 cm maximum size). The deposit underwent pedogenesis which altered the surface of the clasts and the whole sediment structure, and determined the formation of Fe-Mn concretions. Unit 7: alluvial deposit made of polygenic gravel (cm-size pebbles) laterally grading to clayey silt with sparse pebbles. The pebbles lithology attests that the deposit has been fed by the Tagliamento R. catchment.. Unit 8: bedrock represented by the Savorgnano Flysch (Ypresian, Early Eocene). Table 2: (INNOVA SCARL laboratory). Centro per lo Sviluppo ed il trasferimento dell'Innovazione nel Settore dei Beni culturali e Ambientali-INNOVA Scarl. Via Cairoli 81,