Imaging continental shelf shallow stratigraphy by using different high-resolution seismic sources: an example from the Calabro-Tyrrhenian margin (Mediterranean Sea)

High-resolution seismic reflection profiles of the Calabro-Tyrrhenian continental shelf were collected using different seismic sources (Sub-Bottom Profiler, Uniboom, Sparker 0.5-1-4.5 kJ). Noticeable differences and results were obtained both from a geophysical and geological-interpretative point of view. The availability of different sources permitted the definition of the most suitable seismostratigraphic characterization in terms of resolution, penetration and acoustic facies. Very high resolution stratigraphy was defined through profiles produced by different seismic systems used in parallel. This permitted the application of sequence-stratigraphy concepts with the reconstruction of a thick postglacial depositional sequence, formed by a transgressive and a high-stand systems tract. The thickness distribution of postglacial deposits reveals that the main depocenter (55-65 m) is located offshore of the Coastal Range, along a stretch of coast supplied by several small and seasonal streams ("fiumare") and characterized by the lack of a coastal plain. This suggests the greater efficiency of sediment supply and bypass in this area relatively to sectors located offshore of the main rivers. The transgressive systems tract, usually thin or nearly absent, is particularly well developed (up to 33 m) and is composed of up to three parasequences with a retrogradational stacking pattern. The high-stand systems tract, up to 30 m thick, is made up of two parasequences and has a quite regular geometry and acoustic facies

Digenean trematodes of Seriolella porosa (Pisces, Centrolophidae) in San Matías Gulf, Argentina

Seriolella porosa (Silver warehou) is an important fish resource in the Argentine Sea. No previous studies have been carried out to date on its parasite fauna. The present study aims to (i) identify the digenean trematodes that parasitize Silver warehou, (ii) estimate parasite frequency and abundance, and (iii) establish their relationship with fish size and sex. A total of 100 specimens of S. porosa from San Matías Gulf, Argentina were examined between September and October 2006. Host size and sex were determined. Parasites extracted from the stomach lumen were fixed, conserved in 5% formalin, and stained with Langeron's hydrochloric carmine. The following parameters were also determined: dispersion coefficient, prevalence, intensity, and parasite abundance. Differences in parasitism were assessed using non-parametric tests. Four adult digenean species were found in the stomach, namely Lecithocladium cristatum, Aponurus laguncula, Elytrophalloides oatesi and Gonocerca cf. phycidis. L. cristatum was not only dominant but also the most prevalent and abundant species. None of the digeneans showed interspecific association with each other and therefore they might follow different patterns of colonization (i. e., different intermediate hosts, seasonal and/or spatial distribution of the infective stages). Significant differences were observed among the digeneans analyzed in respect to the sex of the host. Results from this study show that Silver warehou plays a key role as a final host of a significant number of digeneans in the ecosystem. This study is the first step in an attempt to further determine the larval stages in intermediate hosts in San Matías Gulf.Centro de Estudios Parasitológicos y de Vectore

Digenean trematodes of Seriolella porosa (Pisces, Centrolophidae) in San Matías Gulf, Argentina

Seriolella porosa (Silver warehou) is an important fish resource in the Argentine Sea. No previous studies have been carried out to date on its parasite fauna. The present study aims to (i) identify the digenean trematodes that parasitize Silver warehou, (ii) estimate parasite frequency and abundance, and (iii) establish their relationship with fish size and sex. A total of 100 specimens of S. porosa from San Matías Gulf, Argentina were examined between September and October 2006. Host size and sex were determined. Parasites extracted from the stomach lumen were fixed, conserved in 5% formalin, and stained with Langeron's hydrochloric carmine. The following parameters were also determined: dispersion coefficient, prevalence, intensity, and parasite abundance. Differences in parasitism were assessed using non-parametric tests. Four adult digenean species were found in the stomach, namely Lecithocladium cristatum, Aponurus laguncula, Elytrophalloides oatesi and Gonocerca cf. phycidis. L. cristatum was not only dominant but also the most prevalent and abundant species. None of the digeneans showed interspecific association with each other and therefore they might follow different patterns of colonization (i. e., different intermediate hosts, seasonal and/or spatial distribution of the infective stages). Significant differences were observed among the digeneans analyzed in respect to the sex of the host. Results from this study show that Silver warehou plays a key role as a final host of a significant number of digeneans in the ecosystem. This study is the first step in an attempt to further determine the larval stages in intermediate hosts in San Matías Gulf.Centro de Estudios Parasitológicos y de Vectore

Basin-scale interaction between post-LGM faulting and morpho-sedimentary processes in the S. Eufemia Gulf (Southern Tyrrhenian Sea)

The integrated interpretation of high-resolution multibeam bathymetry, seismic profiles and backscatter data in the S. Eufemia Gulf (SEG; Calabro-Tyrrhenian continental margin, south-eastern Tyrrhenian Sea) documents the relationship between postglacial fault activity and morpho-sedimentary processes. Three systems of active normal faults that affect the seafloor or the shallow subsurface, have been identified: 1) the S. Eufemia fault system located on the continental shelf with fault planes mainly oriented N26E-N40E; 2) the offshore fault system that lies on the continental slope off Capo Suvero with fault planes mainly oriented N28E-N60E; 3) the Angitola Canyon fault system located on the seafloor adjacent to the canyon having fault planes oriented N60EN85E. The faults produce a belt of linear escarpments with vertical displacement varying from a few decimeters to about 12 m. One of the most prominent active structures is the fault F1 with the highest fault length (about 9.5 km). Two main segments of this fault are identified: a segment characterised by seafloor deformation with metric slip affecting Holocene deposits; a segment characterised by folding of the seafloor. A combined tectonostratigraphic model of an extensional fault propagation fold is proposed here to explain such different deformation.In addition to the seabed escarpments produced by fault deformation, in the SEG, a strong control of fault activity on recent sedimentary processes is clearly observed. For example, canyons and channels frequently change their course in response to their interaction with main tectonic structures. Moreover, the upper branch of the Angitola Canyon shows straight flanks determined by fault scarps. Tectonics also determined different sediment accumulation rates and types of sedimentation (e.g., the accumulation of hanging wall turbidite deposits and the development of contourite deposits around the Maida Ridge). Furthermore, the distribution of landslides is often connected to main fault scarps and fluids are locally confined in the hanging wall side of faults and can escape at the seabed, generating pockmarks aligned along their footwall

Towards Critical Occidentalism Studies: Re-inventing the 'West' and 'Japan' in Mangaesque Popular Cultures

This paper investigates the reproduction of the imagined geography of the ‘West’ in contemporary Japan by employing a relational, intersectional and positional approach in order to examine Occidentalism and its hegemonic identification and othering process. Particular attention will be paid to emerging Japanese subcultures enacting a parodic and sexualised re-invention of Westernness and Japaneseness within a globalising mangaesque media mix

An Integrated Multiscale Method for the Characterisation of Active Faults in Offshore Areas. The Case of Sant\u2019Eufemia Gulf (Offshore Calabria, Italy)

Diagnostic morphological features (e.g., rectilinear seafloor scarps) and lateral offsets of the Upper Quaternary deposits are used to infer active faults in offshore areas. Although they deform a significant seafloor region, the active faults are not necessarily capable of producing large earthquakes as they correspond to shallow structures formed in response to local stresses. We present a multiscale approach to reconstruct the structural pattern in offshore areas and distinguish between shallow, non-seismogenic, active faults, and deep blind faults, potentially associated with large seismic moment release. The approach is based on the interpretation of marine seismic reflection data and quantitative morphometric analysis of multibeam bathymetry, and tested on the Sant\u2019Eufemia Gulf (southeastern Tyrrhenian Sea). Data highlights the occurrence of three major tectonic events since the Late Miocene. The first extensional or transtensional phase occurred during the Late Miocene. Since the Early Pliocene, a right-lateral transpressional tectonic event caused the positive inversion of deep (>3 km) tectonic features, and the formation of NE-SW faults in the central sector of the gulf. Also, NNE-SSW to NE-SW trending anticlines (e.g., Maida Ridge) developed in the eastern part of the area. Since the Early Pleistocene (Calabrian), shallow (<1.5 km) NNE-SSW oriented structures formed in a left-lateral transtensional regime. The new results integrated with previous literature indicates that the Late Miocene to Recent transpressional/transtensional structures developed in an 3cE-W oriented main displacement zone that extends from the Sant\u2019Eufemia Gulf to the Squillace Basin (Ionian offshore), and likely represents the upper plate response to a tear fault of the lower plate. The quantitative morphometric analysis of the study area and the bathymetric analysis of the Angitola Canyon indicate that NNE-SSW to NE-SW trending anticlines were negatively reactivated during the last tectonic phase. We also suggest that the deep structure below the Maida Ridge may correspond to the seismogenic source of the large magnitude earthquake that struck the western Calabrian region in 1905. The multiscale approach contributes to understanding the tectonic imprint of active faults from different hierarchical orders and the geometry of seismogenic faults developed in a lithospheric strike-slip zone orthogonal to the Calabrian Arc

Mid-to-late Holocene upper slope contourite deposits off Capo Vaticano (Mediterranean Sea): High-resolution record of contourite cyclicity, bottom current variability and sandy facies

none13noThe upper continental slope offshore Capo Vaticano (southern Tyrrhenian Sea) is characterized by a contourite depositional system with well-developed elongated sediment drifts. This system is related to a northward paleo-bottom current, similar to the present-day modified-Levantine Intermediate Water (modified-LIW) flowing from the Messina Strait. In this work, we show results from an integrated analysis of descriptive oceanography, high-resolution seismic profiles and core data (i.e., grain size, foraminiferal assemblages, tephrostratigraphy and AMS radiocarbon dating) collected from the crest and moat sectors of drift deposits. The studied succession formed since the mid Holocene, under the action of the modified-LIW and the stratigraphic architecture indicates an upslope migration of the moat and rather stable position of the crest sector. Grain-size features recorded from two sediment cores indicate the occurrence of a succession of complete bi-gradational sand-rich contourite sequences. Sandy facies were observed both as lag deposits formed in active moat channel and as coarser intervals of bi-gradational sequences forming drift deposits close to its crest. Their occurrence would highlight that upper slope environments impacted by intermediate water masses and proximal to sandy sources may represent favorable settings for accumulation of sandy sediment. The moat sector is characterized by a more complex stratigraphic record, where either moat sedimentation or lateral deposition of finer sediment occur, suggesting that further investigation is required to better understand this complex element of contourite systems. Based on available age information, some of the bi-gradational sequences probably formed during the Dark Age Cold Period, providing example of a small-scale cyclicity of contourite deposition, likely related to short-term (possibly multicentennial scale) fluctuations of the paleo modified-LIW. According to age constraints and analysis of foraminiferal assemblages, these fluctuations were likely governed by climate variations, with a weaker activity during warmer periods and faster currents during colder events.openMartorelli E., Bosman A., Casalbore D., Chiocci F., Conte A.M., Di Bella L., Ercilla G., Falcini F., Falco P., Frezza V., Gaglianone G., Giaccio B., Mancini M.Martorelli, E.; Bosman, A.; Casalbore, D.; Chiocci, F.; Conte, A. M.; Di Bella, L.; Ercilla, G.; Falcini, F.; Falco, P.; Frezza, V.; Gaglianone, G.; Giaccio, B.; Mancini, M

Digenean trematodes of Seriolella porosa (Pisces, Centrolophidae) in San Matías Gulf, Argentina

Seriolella porosa (Silver warehou) is an important fish resource in the Argentine Sea. No previous studies have been carried out to date on its parasite fauna. The present study aims to (i) identify the digenean trematodes that parasitize Silver warehou, (ii) estimate parasite frequency and abundance, and (iii) establish their relationship with fish size and sex. A total of 100 specimens of S. porosa from San Matías Gulf, Argentina were examined between September and October 2006. Host size and sex were determined. Parasites extracted from the stomach lumen were fixed, conserved in 5% formalin, and stained with Langeron's hydrochloric carmine. The following parameters were also determined: dispersion coefficient, prevalence, intensity, and parasite abundance. Differences in parasitism were assessed using non-parametric tests. Four adult digenean species were found in the stomach, namely Lecithocladium cristatum, Aponurus laguncula, Elytrophalloides oatesi and Gonocerca cf. phycidis. L. cristatum was not only dominant but also the most prevalent and abundant species. None of the digeneans showed interspecific association with each other and therefore they might follow different patterns of colonization (i. e., different intermediate hosts, seasonal and/or spatial distribution of the infective stages). Significant differences were observed among the digeneans analyzed in respect to the sex of the host. Results from this study show that Silver warehou plays a key role as a final host of a significant number of digeneans in the ecosystem. This study is the first step in an attempt to further determine the larval stages in intermediate hosts in San Matías Gulf.Centro de Estudios Parasitológicos y de Vectore

Geohazard features of the Tyrrhenian Calabria

This paper accompanies the Maps of Geohazard features of the Cilento and the Calabro-Tyrrhenian continental margin in the southern Tyrrhenian Sea (Italy). The main geohazard-related features were derived from extensive seafloor mapping through the collection of high-resolution multibeam data acquired during several oceanographic cruises. They encompass many fluids seepage features, fault scarps, landslides scars, gullies, channels, and canyons. Hazards related to coastal landslides and shelf-indenting canyons are very high in these sectors (especially in southern Calabria) due to active seismicity coupled with rapid uplift, high sedimentation rates and narrow or totally absent continental shelf, thus promoting a direct connection between steep slopes and coastal areas. In this setting, mass-wasting features can directly impact coastal or submarine infrastructures or indirectly create local tsunami waves, as observed in historical times. Moreover, this physiographic setting of the margin facilitates the transfer of marine litter toward deep-sea areas