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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 m 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 m/s. A ~0.1 m/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 structures. [ABSTRACT FROM AUTHOR]

A 3D active and passive seismic survey was carried over an aquifer in Italy. We used 1-component vertical receivers in a fine areal grid of 100x100 m. Furthermore, two orthogonal linear profiles were acquired with 3-component receivers, recording the signal of a directional vibrator in the x, y and z direction, so getting a 9-component wave field. The data allow studying the elastic propagation effects of seismic waves in the aquifer, getting independent measurements of direct P, SH and SV arrivals. The elastic parameters they provide allow exploiting the Rayleigh wave velocities obtained by passive seismic for aquifer monitoring. [ABSTRACT FROM AUTHOR]

In the framework of WAter Re-BOrn Project a large pond in Mereto (upper Friuli plain) was chosen as artificial recharge test site. Several geophysical investigations (GPR, Electrical Resistivity Tomography and High Resolution Seismic) were carried out to study and to characterize the vadose zone of this large infiltration basin. These geophysical integrated methods supplied us many information to characterize the vadose zone and the unconfined aquifer in the study area. The geophysical information greatly reduces the hydrogeological knowledge gaps and was used to improve the three-dimensional Finite Element numerical model to predict the effect of the artificial recharge. [ABSTRACT FROM AUTHOR]

Recent studies revealed the emission of fluids from the seafloor at various locations in the Gulf of Trieste (northern Adriatic Sea). To image the shallow sediments where this happens, several Chirp surveys were carried out. The shallow water reverberations limited the interpretation of this data, so we set up a workflow that attenuated the multiple reflections significantly. The new images of the shallow formations allowed improving our understanding of the most recent geological phenomena. Also, faint reflections from water layers with different acoustic impedance, probably due to temperature differences, were revealed, and several plumes were imaged. These images allow linking the shallow stratigraphy of the seafloor to ongoing fluids' emissions. [ABSTRACT FROM AUTHOR]

The intrusion of relatively warm water onto the continental shelf is widely recognized as a threat to Antarctic ice shelves and glaciers grounded below sea level, as enhanced ocean heat increases their basal melt. While the circulation of warm water has been documented on the East Antarctic continental shelf, the modes of warm water transport from the deep ocean onto the shelf are still uncertain. This makes predicting the future responses of major East Antarctic marine-grounded glaciers, such as Totten and Ninnis glaciers, particularly challenging. Here, we outline the key role of submarine canyons to convey southward flowing currents that transport warm Circumpolar Deep Water toward the East Antarctic shelf break, thus facilitating warm water intrusion on the continental shelf. Sediment drifts on the eastern flank of the canyons provide evidence for sustained southward-directed flows. These morpho-sedimentary features thus highlight areas potentially prone to enhanced ocean heat transport toward the continental shelf, with repercussions for past, present, and future glacial melting and consequent sea level rise., (© 2024. The Author(s).)

The Pantelleria Vecchia Bank is a submerged calcareous-arenitic shoal in the NW sector of the Sicilian Channel. Together with other morphological heights, some of which are volcanic in origin, this shoal punctuates the shallow Adventure Plateau, which was above sea level from the Last Glacial Maximum until at least 9000 years ago. The rise in sea level caused by the melting of the ice caps gradually flooded the plateau, isolating the heights and creating a broad archipelago until the area was finally submerged. High-resolution Multibeam bathymetric mapping shows that the Pantelleria Vecchia Bank has an 820 m long rectilinear ridge connecting the two main shoals of the bank, and an 82 m long ridge perpendicular to the 820 m ridge 100 m from its southern end. The top of the 820 m ridge lies in a water depth of 35 m, its base in about 42 m, and the seaward side has a fairly uniform slope of 16°-22°. The 82 m ridge has an average width of ∼7 m and rises ∼1 m above the surrounding seafloor. Underwater photographs document that the entire seaward side of the 820 m ridge consists of juxtaposed blocks, the largest measuring about 3 × 4 m, some of which are rectangular in shape, while the upper part consists of horizontally arranged blocks and the lower part of sub-vertical blocks embedded in the sediments. Petrographic analyses show that the blocks forming the seaward side of the 820 m ridge can be classified as late Pleistocene calcirudites, while the 82 m ridge consists of bioclastic calcarenites of Tortonian age. A series of high-resolution seismic profiles crossing both ridges and composite mosaics of the seafloor obtained from underwater videos provide a comprehensive panorama of these two peculiar and in many ways enigmatic structures. The structures described and the palaeogeographical context in which they are embedded do not exclude the possibility that they are artefacts indicating an ancient temporary or permanent human presence in the Pantelleria Vecchia Bank., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors. Published by Elsevier Ltd.)

Perito Moreno is the most famous calving glacier of the South Patagonia Icefield, the largest temperate glacier system of the Southern Hemisphere. Unlike most of the glaciers in the region that have strongly retreated in recent decades, the position of Perito Moreno glacier front remained relatively unchanged in the last century. However, earliest photographic documents show that, at the end of the nineteenth century, the front was ca. 800 m behind the current position. There is no reliable information about the positions of the Perito Moreno front in earlier times. Here we show evidence of two subaqueous moraine systems both in the Canal de Los Témpanos and in the Brazo Rico, the two arms of Lago Argentino along which Perito Moreno glacier has flowed over time. These moraines, identified for the first time in the Canal de Los Témpanos from bathymetric and high-resolution seismic profiles, mark the position of the largest glacier advance, tentatively correlated with the moraines of the "Herminita advance" identified and dated onland. We interpret these bedforms as the evidence of the most pronounced advance of Perito Moreno glacier during the mid-Holocene cooling event that characterized this sector of the Southern Hemisphere. This study highlights the importance of subaqueous glacial bedforms, representing decisive records of the glacial history and palaeoclimate, which could help unveiling the origin of the different behavior of glaciers like Perito Moreno that in a warming climate are relatively stable.

We provide a model for the genesis of Holocene coralligenous buildups occurring in the northwestern Adriatic Sea offshore Venice at 17-24 m depth. High-resolution geophysical surveys and underwater SCUBA diving reconnaissance revealed meandering shaped morphologies underneath bio-concretionned rocky buildups. These morphologies are inferred to have been inherited from Pleistocene fluvial systems reactivated as tidal channels during the post- Last Glacial Maximum transgression, when the study area was a lagoon protected by a sandy barrier. The lithification of the sandy fossil channel-levee systems is estimated to have occurred at ca. 7 cal. ka BP, likely due to the interaction between marine and less saline fluids related to onshore freshwater discharge at sea through a sealed water-table. The carbonate-cemented sandy layers served as nucleus for subsequent coralligenous buildups growth.