Sicilian Channel Research Articles

Ferula sommieriana (Apiaceae), a new species from Pelagie Islands (Sicily)

Ferula sommieriana, a new species occurring in Lampedusa and Linosa, islands of Pelagie Archipelago in the Sicilian Channel, is described and illustrated. Previously it was attributed to F. communis, from which it differs in several features regarding mainly the morphology and anatomy of terminal leaf lobes and mericarps, as well as the shape and size of reproductive structures. Its ecology, conservation status and relationships with other allied Mediterranean species of the sect. Ferula are provided, as well as the analytical keys of the species belonging to the aforesaid section.

Spatial genetic patterns of Octopus vulgaris Mediterranean populations support the hypothesis of a transitional zone across the Siculo-Tunisian Strait

Recent research hypothesised that the Siculo-Tunisian Strait might fit, at least for some species, the picture of a genetic transitional zone instead of a sharp genetic break between the Western and Eastern Mediterranean basins. The present study aimed at using the common Octopus, Octopus vulgaris as an empirical test-case to evaluate this hypothesis. To accomplish this goal, 458 new sequences of the mitochondrial gene cytochrome c oxidase subunit I were used. Combining the new sequences with those available on public databases, we assembled a dataset containing 920 sequences to investigate the spatial genetic patterns across 34 Mediterranean populations of O. vulgaris. The genetic structure of this species was assessed combining analysis of molecular variance and Median-Joining networks. Results supported the hypothesis of a complex spatial genetic pattern across the Sicilian channel. Contemporary factors, such as marine currents, likely affect the species’ genetic structuring across this area. Overall, our results highlighted that focusing the attention on the whole transitional area rather than on a unique genetic break might help to detect similar patterns across different species. Finally, acknowledging the occurrence of complex spatial genetic patterns across transitional zones may improve stock identification and management practices for commercially valuable species.

Artisanal fishing, dolphins, and interactive pinger: A study from a passive acoustic perspective

Abstract Dolphins interact with many types of fishing gear, causing damage to fishing activities and in some cases facing harm and becoming entangled as bycatch. In this study, the behaviour of bottlenose dolphins during their interaction with set nets, equipped with and without interactive pingers, was investigated. Acoustic monitoring of the nets was conducted for a total of 56 hauls and 814.9 hr of recordings, from the 16 October to 13 November 2015, along the coast of Lampedusa island (Sicilian Channel, Italy, Mediterranean Sea). The level of interaction between dolphins and the nets was evaluated considering the number of dolphin clicks grouped over time (single acoustic incursion on each net), the duration of every acoustic incursion, and the number of dolphin clicks per incursion. Moreover, the catch rate was measured as the number of fish per hour for each net. Based on the recording time of dolphin clicks, the spatio‐temporal development of the interaction with the nets located in different bays of the island was assessed. The duration of the interaction between dolphins and nets significantly increased over the study period, with a concomitant reduction in catch rate. The interactive pinger showed efficacy in protecting the nets from dolphin depredation during the first period of 36 hauls and 11 fishing days (higher catch rates and lower incursion durations), whereas no differences were found in any interaction parameters between pinger and control nets in the second period (20 hauls and six fishing days). Interactive pingers may be an effective, short‐term (2–3 weeks) tool in deterring depredation by bottlenose dolphins in small‐scale artisanal fisheries. Other mitigation approaches, such as gear modification, lessons learned through outreach, and passive acoustic monitoring of the nets, could improve the management of the interactions between fisheries and bottlenose dolphins.

Unraveling Past Submarine Eruptions by Dating Lapilli Tuff-Encrusting Coralligenous (Actea Volcano, NW Sicilian Channel)

The dating of young submarine volcanic eruptions, with their potential generation of tsunamigenic waves, is essential for a reliable hazard assessment. This is particularly relevant in highly populated coastal areas. The scarce knowledge of the underwater environment makes however, this reconstruction challenging. Our study is focused on the NW sector of the Sicilian Channel, where several small- and medium-size volcanic edifices are present. The only documented Surtseyan-type eruption occurred in A.D. 1831, forming the ephemeral Ferdinandea Island. Late Pleistocene to mid-Holocene eruptions have been up to now only hypothesized, and based solely on indirect data. Here we present the first radiocarbon dates of a coralligenous bioconstruction sampled at 34 m water depth from the summit of the Actea volcano, grown up progressively (up to nowadays) on a lapilli tuff deposit. Actea volcano is a recently discovered pyroclastic cone located at only four nautical miles off the SW coast of Sicily. The oldest age of the bioconstructions that started to encrustate the shallow water pyroclastics shortly after their emplacement (7,387 ± 175 cal years B.P.) represents a terminus ante quem, thus testifying a mid-Holocene submarine eruption in this sector of the Sicilian Channel. This method may be effectively used to bridge the gap between historical accounts and the geological record and thus may contribute to a better volcanic hazard assessment of submarine eruption and related phenomena such as tsunamis.

A new species for the Italian fauna: Aphaenogaster strioloides, not A. crocea, inhabits Pantelleria Island (Hymenoptera: Formicidae)

Species of the recently recognized Aphaenogaster crocea group, which spreads across Canary Islands, Maghreb region and Southern Italy, have frequently been confused with one another and even with species belonging to other groups. We revised the identity of the population previously attributed to A. crocea from the island of Pantelleria (Sicilian Channel) by comparing voucher specimens of the older records as well as newly collected specimens with type specimens and descriptions of the other members of the group. As a result, we re-identify the population from Pantelleria as A. strioloides, a species so far known to occur exclusively in Algeria and Tunisia. Fi- nally, we discuss the key diagnostic features of this species.

Local and Regional Wind Patterns Affect Spring Migration Magnitude, Flyways and Flocking Of European Honey-Buzzards Pernis apivorus at the Strait of Messina

During spring migration, a few tens of thousands of European Honey-buzzards wintering in sub-Saharan Africa cross the central Mediterranean to reach their breeding grounds in central-eastern Europe. In so doing they concentrate passage through the Sicilian Channel but choose different flyways in response to different wind conditions. This study investigated the influence of local and regional wind conditions on the movement patterns of this species along the Strait of Messina, a migration bottleneck located between eastern Sicily and southern continental Italy where some raptors fall victim to illegal shooting by poachers each spring. Simultaneous observations occurred at four watchpoints, three on the Sicilian side and one on the continental boundary (Calabrian side). Although northwesterly winds prevailed at the Strait during peak migration days, slightly different local patterns of both horizontal and vertical winds at each observation site affected flocking and shaped the passage of raptors through this bottleneck, broadening the migration front. The results confirm that the magnitude of Honey-buzzard spring migration at the Strait is strongly affected by wind patterns in the Sicilian Channel. In particular, migrants concentrate at this bottleneck after crossing the Channel in northwesterly winds the previous day. In conclusion, by interpreting migratory behaviour both at local and regional scales, this work can help to plan more efficient monitoring of Honey-buzzards through the Strait and improving the siting of conservationist efforts. —Agostini, N., Chiatante, G., Gustin, M., Cento, M., von Hardenberg, J., Dell'Omo, G. & Panuccio, M. (2021). Local and regional wind patterns affect spring migration magnitude, flyways and flocking of European Honey-buzzards Pernis apivorus at the Strait of Messina. Ardeola, 68: 373-390.

Morphostructural Setting and Tectonic Evolution of the Central Part of the Sicilian Channel (Central Mediterranean)

Abstract The Plio-Quaternary tectonic evolution of the central sector of the Sicilian Channel and the resulting morphostructural setting have been analyzed using a large geophysical dataset consisting of multichannel seismic profiles, which some of them never published, and available bathymetric data. This area hosts two regional-scale tectonic domains that registered the complex pattern of deformation occurred since the Early Pliocene: (1) the Sicilian Channel Rift Zone (SCRZ), which can be divided into a western sector formed by the Pantelleria graben (PG) and in a eastern one represented by the Linosa and Malta grabens (LG and MG) and (2) the Capo Granitola-Sciacca Fault Zone (CGSFZ), a NNE-oriented lithospheric transfer zone that crosses the Sicilian Channel from the Sicily coast to the Linosa Island, of which only its northern part has been studied to date. Data interpretation has allowed achieving the following outcomes: (i) the presence of an alternation of basins and structural highs forming a NNE-oriented separation belt between the western and eastern sectors of the SCRZ, and interpreted as the shallow expression of the southern part of the CGSFZ; (ii) a NE-oriented tectonic lineament separating the MG in a northern and southern part, and interpreted as the southern prosecution of the Scicli-Ragusa Fault System; (iii) the presence of syn-rift deposits in the Plio-Quaternary fill of the grabens, suggesting that the opening of the grabens of the SCRZ was coeval, and started since Early Pliocene in the framework of a NW-oriented right-lateral transtensional mega-shear zone; (iv) continental rifting ended around the Early Calabrian, during which extensional tectonics dominated along the separation belt; (v) the CGSFZ conditioned the SCRZ configuration at a regional scale, leading to the development of the PG in the western sector and of the LG and MG in the eastern one; and (vi) after the Early Calabrian, the PG and the southern MG followed a different tectonic evolution with respect to the LG and northern MG. The syn-rift deposits of the PG and southern MG were sealed by an undeformed post-rift succession, while the LG and the northern MG suffered a basin inversion that ended around the Latest Calabrian time. During this stage, the separation belt was affected by a transpressional tectonics. At present, the grabens of the Sicilian Channel seem to be tectonically inactive, while the CGSFZ represents an active tectonic domain.

Evaluation of Brassicaceae Seedlings as Trap Plants for Bagrada Hilaris Burmeister in Caper Bush Cultivations

The caper bush, Capparis spinosa (Brassicales: Capparaceae), is intensively grown on Pantelleria Island (Trapani, Sicily, Sicilian channel) where it has been granted protected geographical indication (PGI) by the EU. On this island, Bagrada hilaris, a stink bug native of Asia and Africa, is the major pest of caper crops. Recent studies have shown the attraction of B. hilaris to volatiles of brassicaceous plants at the seedling stage. The objective of this study was to evaluate three cotyledon-stage seedlings of host plants, Brassica oleracea var. botrytis (cauliflower), Eruca sativa (rocket) and Brassica carinata (Abyssinian cabbage), as potential trap plants for B. hilaris. The relative preferences of these species were first evaluated in laboratory and field experiments, carried out during summer when the level of B. hilaris infestation was the highest. Behavioral bioassays in the laboratory conditions showed that adults of B. hilaris preferred to orient toward seedlings of B. oleracea and E. sativa over B. carinata. Field experiments confirmed these results. Then seedlings were tested in trap plant trials, by sowing them in artificial pots formed with aluminum trays and placing them in caper fields infested with B. hilaris. Results showed that E. sativa and B. oleracea diverted hundreds of B. hilaris individuals from the capers to these sources of attraction. Overall, these results suggest that B. oleracea and E. sativa seedlings used as lure inside traps or as trap plants may be a useful tool in the management of B. hilaris populations.

Archaeology of Contemporary Migrant Journeys in Western Sicily

The Sicilian Channel between Sicily and North Africa receives global attention as a major migratory routefor undocumented people entering Europe clandestinely, a tragic nexus of transnational displacement anddesperation. While the plight of massively overloaded and unseaworthy boats of people justifiably receivesthe bulk of media attention, there is a less-observed movement that occurs and has occurred for thousandsof years: small boats expertly transporting handfuls of people back and forth across the Channel betweenTunisia and western Sicily. This study explores the material vestiges of cross-channel migrations throughassemblages identified during fieldwork by the Arizona Sicily Project along the southwest coast of Sicily inthe summers of 2018 and 2019. While the exigencies of maritime crossing require distinct technologies ofmobility, certain elements of migrant material culture are analogous to that found elsewhere, e.g. along theUS-Mexico border zone of Arizona's Sonoran Desert. Such elements include migrants' strategic triangulationof speed, invisibility and survival in deciding what to bring and the tactical triage of gear en route.Moreover, the political and economic injustices that are catalysts for the movements are comparable, as is thecriminalization of the migrants, which has done more to endanger than dissuade them. This article shedsnew light on migrant choices and challenges and contributes to the archaeology of contemporary migration.

The interaction between strike-slip dominated fault zones and thrust belt structures: Insights from 4D analogue models

Strike-slip motion is a fundamental tectonic process around the globe often resulting in prominent surface expressions. The full reconstruction and comprehension of strike-slip dominated structures can be a major challenge due to the complexity of the associated fault patterns. Further complexities occur when strike-slip dominated structures in the foreland interact with thrust belt fronts. Starting from a well-studied natural example (the Sciacca Fault Zone in the Sicilian Channel, Italy) we ran a set of analogue models simulating the interaction between strike-slip dominated fault zones and thrust structures using quartz sand as the analogue material and X-Ray Computed Tomography as a technique to carry out a 4D analysis of model internal structures. During a first phase, a thrust belt was created in our models, which was subsequently affected by a perpendicular fault system that underwent either pure strike-slip, 10°-, 20°-, 30°-transtensional, or 10°-, 20°-, 30°-transpressional motion. In general, transpressional models form pop-up structures, while the pure strike-slip model develops one sub-vertical fault bounded by two converging reverse faults. The 10˚-transtensional model generates a set of Riedel shear faults, which merge during the later stages of deformation. This model also shows a positive elevation change along the strike-slip dominated structures near the intersection with the thrust belt. The 20˚-transtensional model contains some Riedel shear faulting as well, but is dominated by two normal faults with steep dip angles and some minor sub-vertical strike-slip faults in between. This fault architecture is also observed in our 30˚-transtensional model. Three different tectonic regimes interacting with pre-existing and newly formed thrust front led to very different structural settings. These results were of help in better defining the tectonic regime that controlled the strike-slip dominated part of the Sciacca Fault Zone, but they show a fair match with other natural examples as well.

The Graham and Terrible volcanic province (NW Sicilian Channel): gravimetric constraints for the magmatic manifestations

A few kilometres off the SW coast of Sicily lie the shallow banks of Graham, Terrible and Nerita. These morphological reliefs are affected by two lithospheric scale, N–S trending tectonic lineaments known as Capo Granitola to the west and Sciacca to the east. Within the Graham and Terrible banks, several volcanic edifices have been documented and mapped using high-resolution bathymetry and seismic profiles. Three groups of volcanic features can be distinguished: (i) a cluster of N–S aligned volcanic cones in the Graham Bank, generally developed along the Capo Granitola fault, (ii) a series of poorly developed volcanic constructs roughly positioned along the northern edge of the Terrible Bank, and (iii) a few isolated volcanic centres located north of the Terrible Bank, within an undeformed zone. Here we present a 2-D gravimetric model, constrained at shallow levels by an integrated seismic dataset, which we use to interpret the distribution of magmatic manifestations in this sector of the Sicilian Channel. At the Graham Bank, where there are no significant positive gravity anomalies, the magmatic material seem to migrate to the surface along the Capo Granitola lithospheric fault, without the presence of a shallow magma source. In the Terrible Bank, where there is a well-defined positive gravity anomaly, the model implies the presence of a shallow magma chamber from which sea-floor volcanic constructs are fed upwards along cracks. The origin for the volcanic cones located between the two fault systems is more problematic, as no significant structural discontinuities were identified in this area from the available seismic data. However, the presence of a potential wide sill complex suggests that it facilitated lateral magma flow from source to surface over lateral distances of tens of kilometres.

Some Reports of Paratethyan Ostracods from the Central Mediterranean Area

Uppermost Miocene stratigraphic sections have been sampled in Sicily and eastern Tunisia. Some of the stratigraphic levels contained in them are related to the continentalization phase (“Lago Mare”) of the Mediterranean Basin, which occurred at the end of the Messinian Salinity Crisis. Within these levels, ostracod associations reflecting fresh or brackish water environments are reported here for the first time. Species considered to be Paratethyan in affinity lived in these environments. The discovery, both in Sicily and Tunisia, of species such as C agrigentina, A propinqua, and M. punctate, suggests that the Sicilian Channel did not prevent the migration of the non-marine fauna from NW to SE in the Paleomediterranean area during the Post Evaporitic Phase

Micro-chemical investigation of corrosion products naturally grown on archaeological Cu-based artefacts retrieved from the Mediterranean sea

The corrosion products naturally formed on archaeological Cu-based artefacts during their long-term exposure to seawater have been investigated in details by means of X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive spectrometry (SEM + EDS), optical microscopy (OM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), differential thermal analysis-thermogravimetry (DTA-TG), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray photoelectron spectroscopy (XPS). The bronze artefacts include fragments of valuable statues and objects that were retrieved some decades ago from different seabeds along the Italian coast of the Mediterranean basin including the so called “Punta del Serrone” area (Apulia), the Sicilian channel (Sicily) and the Arburese coast (Sardinia). Our findings show that the alloy matrix is often heavily corroded also in the bulk and reveal the dangerous presence of chlorine from seawater as main dangerous corrosive agent. Chlorine is present as copper nantokite (CuCl) in the inner layers of the patina and is potentially inducing with oxygen and moisture the cyclic and often relentless copper degradation phenomenon commonly called “bronze disease”. The most common corrosion products are also lead carbonate (cerussite, PbCO3) and aragonite (CaCO3), likely related to the large abundance of CO2 in the seawater where is assimilated much more than in fresh water. Furthermore, the results reveal that other environmental elements contributing to the composition of the patina are sulphur, magnesium and phosphorous thus giving rise to a patina with a chemically and structurally complex structure. The results reveal also the contribution of bio-organism to the formation of the patina as supported by the presence of vanadium and copper sulphides. These information allow, as a whole, to propose a tentative correlation between the patina’s nature, the chemical composition and metallurgical features of the alloys and the marine environment where the objects lived for about two thousands years. From a conservation point of view, the findings reported in this work can provide some insights useful to tailor more efficient conservation strategies with the purpose to ensure a long-term chemical-physical stability to the bronze artefacts.

How citizens can encourage scientific research: The case study of bottlenose dolphins monitoring

Citizen science projects are an advantageous method to carry out research in the marine environmental field, especially concerning high mobile and often elusive species like cetaceans, allowing the collection of data in wide spatial-temporal scale. This project aims to validate the feasibility and accuracy of cetacean monitoring program through the citizen science approach and to test the efficiency of this method to large scale study area. In this work data obtained by researchers monitoring were compared with data coming from citizen, which followed specifically developed protocol. Data collected were used to investigate the presence and distribution of bottlenose dolphins (Tursiops truncatus) in the Sicilian Channel and to evaluate the contribution of citizen scientist to improve knowledge about species, in this case for bottlenose dolphin a vulnerable species listed in the Annex II of Habitat Directive (92/43 CE). The results show that citizen dataset contributes to increase the distribution map of the 22% more than only research data were considered. Citizen science programme results useful to gain information in small areas not monitored by scientific programs, such as in this study, and they would be very useful if applied at large-scale. The promotion of citizen science programs in specified small areas could be helpful to cover unmonitored zones, to gain preliminary results and bridge the gap of knowledge about species occurrence and distribution. For this reason, citizen support might help competent authorities to answer to the environmental policies as Habitat Directive and Marine Strategy Framework Directive. This study is a demonstration of how citizen can encourage scientists to start long-term research project in not regularly monitored areas.

Natural history and molecular evolution of demersal Mediterranean sharks and skates inferred by comparative phylogeographic and demographic analyses

BackgroundThe unique and complex paleoclimatic and paleogeographic events which affected the Mediterranean Sea since late Miocene deeply influenced the distribution and evolution of marine organisms and shaped their genetic structure. Following the Messinian salinity crisis and the sea-level fluctuations during the Pleistocene, several Mediterranean marine species developed deep genetic differentiation, and some underwent rapid radiation. Here, we consider two of the most prioritized groups for conservation in the light of their evolutionary history: sharks and rays (elasmobranchs). This paper deals with a comparative multispecies analysis of phylogeographic structure and historical demography in two pairs of sympatric, phylogenetically- and ecologically-related elasmobranchs, two scyliorhinid catsharks (Galeus melastomus, Scyliorhinus canicula) and two rajid skates (Raja clavata, Raja miraletus). Sampling and experimental analyses were designed to primarily test if the Sicilian Channel can be considered as effective eco-physiological barrier for Mediterranean demersal sympatric elasmobranchs.MethodsThe phylogeography and the historical demography of target species were inferred by analysing the nucleotide variation of three mitochondrial DNA markers (i.e., partial sequence of COI, NADH2 and CR) obtained from a total of 248 individuals sampled in the Western and Eastern Mediterranean Sea as well as in the adjacent northeastern Atlantic Ocean. Phylogeographic analysis was performed by haplotype networking and testing spatial genetic differentiation of samples (i.e., analysis of molecular variance and of principal components). Demographic history of Mediterranean populations was reconstructed using mismatch distribution and Bayesian Skyline Plot analyses.ResultsNo spatial genetic differentiation was identified in either catshark species, while phylogeographic structure of lineages was identified in both skates, with R. miraletus more structured than R. clavata. However, such structuring of skate lineages was not consistent with the separation between Western and Eastern Mediterranean. Sudden demographic expansions occurred synchronously during the upper Pleistocene (40,000–60,000 years ago) in both skates and G. melastomus, likely related to optimal environmental conditions. In contrast, S. canicula experienced a slow and constant increase in population size over the last 350,000 years.DiscussionThe comparative analysis of phylogeographic and historical demographic patterns for the Mediterranean populations of these elasmobranchs reveals that historical phylogeographic breaks have not had a large impact on their microevolution. We hypothesize that interactions between environmental and ecological/physiological traits may have been the driving force in the microevolution of these demersal elasmobranch species in the Mediterranean rather than oceanographic barriers.

Capo Granitola-Sciacca Fault Zone (Sicilian Channel, Central Mediterranean): Structure vs magmatism

Abstract The tectonic framework of the northern sector of the Capo Granitola-Sciacca Fault Zone (CGSFZ), a NNE-oriented lithospheric strike-slip fault zone located in the Sicilian Channel (southern Italy), has been reconstructed with the aim to clarify the relationships between geometry and kinematics of the structures and the occurrence and distribution of the magmatic manifestations observed in the area. This has been achieved by the interpretation of a large dataset composed of 2-D multichannel seismic profiles, Chirp profiles, magnetic data and borehole information. In addition to the volcanic edifices known in the Graham and Terribile banks, this study has allowed to recognize several other magmatic manifestations. The magmatic occurrences consist of small volcanic cones, buried magma ascents and potential igneous sills. The CGSFZ is bounded by two strike-slip fault systems, the Capo Granitola Fault System (CGFS) to the west and the Sciacca Fault System (SFS) to the east, dominated by positive flower structures generated by tectonic inversion of NNE-oriented late Miocene extensional faults. Only the southern part of the CGFS shows the presence of a sub-vertical, N-S oriented strike-slip master fault. The sector between the two fault systems does not show a significant Pliocene-Quaternary tectonic deformation, except for its southern part hosting the Terribile Bank, which is dissected by WNW to NW-trending normal faults developed during late Miocene and later reactivated. This set of faults is currently active at the Terribile Bank, whereas is buried by Pliocene-Quaternary deposits in the central and northern sectors of the CGSFZ. The observed magmatism is driven by a mechanism of non-plume origin. Magmas have used as open paths the faults of the CGFS and SFS, which cut the whole lithosphere reaching the asthenosphere and producing partial melting by simple pressure release. Most of the magmatism develops along the strike-slip master fault associated with the CGFS and the normal faults affecting the Terribile Bank. The magmatic feeding of the Terribile Bank would be related to lateral magma migration coming from the structures of the SFS, which would use the open pathways represented by active normal faults. In the central-northern part of the CGSFZ, magmas migrate upward along lithospheric faults, then move laterally and rise toward the surface through NNE and NW-trending buried normal faults. These late Miocene faults do not reach the surface, and this may have favoured the emplacement of igneous sills, which in turn may explain the observed volcanic centres.

Reversing the Trend: a Psychosocial Intervention on Young Immigrants in Sicily

Intervention projects based on providing support for immigrants can offer a number of benefits with regard to the social inclusion of young immigrants. Therefore, the actions suggested in this proposal may not only create a network between institutions and the private sector capable of supporting the intervention of a host country, but may also help to reduce the risk of crime as well as advocating a sense of otherness and integration. The approach to the project, a psychosocial intervention carried out on four young Africans who reached Sicily after crossing the Sicilian Channel on a dilapidated boat, has chiefly been to provide the four individuals with the chance to revisit their original, harrowing voyage, thus allowing them to view the voyage not only as a source of pain and death but also as a source of well-being and mutual understanding. Positive outcomes from the intervention include the satisfaction of the participants and a greater sensitivity towards each other, an awareness of the importance of rules, free time monitoring through utterances, and finally, photographic images for the resulting awareness raising event. The intervention, the only one carried out in Sicilian territory, culminated in the organization of a social visibility day, an event designed to advocate the involvement of local communities and young people. Further, the public event also aimed to raise awareness among the host community to the needs of immigrants, while contributing to discussion on hostile attitudes and closure towards immigrants.

Coupling of Wave Data and Underwater Acoustic Measurements in a Maritime High-Traffic Coastal Area: A Case Study in the Strait of Sicily

AbstractUnderwater acoustic monitoring combined with real-time sea surface observations and numerical model forecasts could improve the efficiency of natural and anthropogenic sound source discrimination. In this work, acoustic sound pressure levels at different frequencies were compared with significant wave heights, measured using an X-band radar system, and then matched against independent data derived from a Simulating Waves Nearshore (SWAN) model in order to confirm their reliability. The acoustic data were recorded from a fixed buoy located in the Sicilian Channel at 4.9 km from the coast and 33 km from the X-band radar system installed at Cape San Marco (in the southwest region of Sicily). All data were acquired during two different periods: 28 February–16 March 2015 and 23 April–27 May 2015. The level of noise at the 16-Hz octave band showed the best linear correlation , with in situ radar observations of significant wave height. Radar measurements of wave height coupled with in situ acoustic measurements give a characterization of the level of noise as result of sea state in a specific area. These measurements could be used to discriminate natural sources of noise (waves) from other sound sources, such as biological and anthropogenic sources. This discrimination contributes to understanding the impact of acoustic pollution on marine environments and provides a monitoring plan protocol for safeguarding biodiversity in the Mediterranean coastal areas.

Structural analysis and Miocene-to-Present tectonic evolution of a lithospheric-scale, transcurrent lineament: The Sciacca Fault (Sicilian Channel, Central Mediterranean Sea)

Seismo-stratigraphic and structural analysis of a large number of multichannel seismic reflection profiles acquired in the northern part of the Sicilian Channel allowed a 3-D reconstruction of a regional NS-trending transfer zone which displays a transcurrent tectonic regime, and that is of broad relevance for its seismotectonic and geodynamic implications. It is constituted of two major transcurrent faults delimiting a 30-km-wide, mostly undeformed basin. The western fault (Capo Granitola) does not show clear evidence of present-day tectonic activity, and toward the south it is connected with the volcanic area of the Graham Bank. The eastern fault (Sciacca) is structurally more complex, showing active deformation at the sea-floor, particularly evident along the Nerita Bank. The Sciacca Fault is constituted of a master and splay faults compatible with a right-lateral kinematics. Sciacca Fault is superimposed on an inherited weakness zone (a Mesozoic carbonate ramp), which borders to the east a 2.5-km-thick Plio-Quaternary basin, and that was reactivated during the Pliocene.A set of scaled claybox analogue models was carried out in order to better understand the tectonic processes that led to the structural setting displayed by seismic data. Tectonic structures and uplift/subsidence patterns generated by the models are compatible with the 3-D model obtained from seismic reflection profiles. The best fit between the tectonic setting deriving from the interpretation of seismic profiles and the analogue models was obtained considering a right-lateral movement for the Sciacca Fault. Nevertheless, the stress field in the study area derived from GPS measurements does not support the present-day modelled right-lateral kinematics along the Sciacca Fault. Moreover, seismic events along this fault show focal mechanisms with a left-lateral component.We ascribe the slip change along the Sciacca Fault, from a right-lateral transcurrent regime to the present-day left-lateral kinematics to a change of principal horizontal stress direction starting from Late Pliocene.

Tropicalization process of the 7 November 2014 Mediterranean cyclone: Numerical sensitivity study

Tropical-like Mediterranean cyclones (medicanes) have been documented and investigated in the literature, revealing that their physical mechanisms are still poorly understood and likely not unique across cases. During late hours of 7 November 2014 a small-scale cyclone was detected over the Sicilian channel, affecting the Islands of Lampedusa, Pantelleria and Malta. Gust wind values exceeding 42.7ms−1 and a pressure drop above 20hPa in 6h were registered in Malta. Clear signatures of a well-defined cloud-free eye surrounded with convective activity of axisymmetric character were identifiable through IR satellite imagery during the late stages of the cyclone, resembling the properties of a hurricane. We investigate the cyclogenesis and posterior development of this small-scale cyclone as well as its physical nature; to this aim, a set of high-resolution sensitivity numerical experiments were performed. Hart's phase diagrams adapted to the Mediterranean region clearly reveal the tropical characteristics of the simulated storm. A numerical sensitivity analysis by means of a factor separation technique is used to gain quantitative insight on the roles latent heat release, surface heat fluxes and upper-level PV signatures (dynamically isolated through a PV-Inversion technique) have on the unfold of this singular event. Results show the importance of the upper-level dynamics to generate a baroclinic environment prone to surface cyclogenesis and in supporting the posterior tropicalization of the system. On the contrary, latent heat release and surface heat fluxes factors do not seem to contribute, as individual processes, to the genesis of the cyclone as much as it could be suspected, considering it behaves as a tropical-like cyclone. However, the asynchronous synergism between latent heat release and PV factors plays a crucial role for the intensification of the cyclone towards reaching the pure diabatic phase.