Microbial Biofilms Along a Geochemical Gradient at the Shallow-Water Hydrothermal System of Vulcano Island, Mediterranean Sea

Shallow water hydrothermal vents represent highly dynamic environments where strong geochemical gradients can shape microbial communities. Recently, these systems are being widely used for investigating the effects of ocean acidification on biota as vent emissions can release high CO2 concentrations causing local pH reduction. However, other gas species, as well as trace elements and metals, are often released in association with CO2 and can potentially act as confounding factors. In this study, we evaluated the composition, diversity and inferred functional profiles of microbial biofilms in Levante Bay (Vulcano Island, Italy, Mediterranean Sea), a well-studied shallow-water hydrothermal vent system. We analyzed 16S rRNA transcripts from biofilms exposed to different intensity of hydrothermal activity, following a redox and pH gradient across the bay. We found that elevated CO2 concentrations causing low pH can affect the response of bacterial groups and taxa by either increasing or decreasing their relative abundance. H2S proved to be a highly selective factor shaping the composition and affecting the diversity of the community by selecting for sulfide-dependent, chemolithoautotrophic bacteria. The analysis of the 16S rRNA transcripts, along with the inferred functional profile of the communities, revealed a strong influence of H2S in the southern portion of the study area, and temporal succession affected the inferred abundance of genes for key metabolic pathways. Our results revealed that the composition of the microbial assemblages vary at very small spatial scales, mirroring the highly variable geochemical signature of vent emissions and cautioning for the use of these environments as models to investigate the effects of ocean acidification on microbial diversity

Unicentric or multicentric castleman disease? A case report of a pelvic intraperitoneal mass in a middle aged woman

Castleman Disease is a lymphoid disorder characterized by the presence of an enlarged or abnormal lymph node/lymphatic tissue. The disease is classified into unicentric or multicentric variants. The unicentric form is a benign disorder that is usually asymptomatic and consists of a single lymphoid mass that is predominantly located in the mediastinum, but can also rarely develop in the neck or abdomen. The multicentric type involves more than one lymphatic station and is related to the presence of type B symptoms (fevers, night sweats and weight loss), HIV/HHV8 infection and increased serum IL-6 levels. We present the case of an unusual pelvic intraperitoneal manifestation of Castleman Disease in a 52-year-old caucasian woman who showed clinical, radiological, histological and laboratory findings common to both Unicentric and Multicentric Castleman Disease

Historical, archeological and geological records of strong earthquakes at Capo Peloro (southern Italy)

During the 4th century AD southern Calabria and eastern Sicily were hit by an earthquake documented by archaeoseismic analyses, which was interpreted by Guidoboni et al. (2000) as the predecessor of the well-know 1908 earthquake, located in Messina Strait, whereas Galli and Bosi (2002) interpreted this event as the precedessor of the 1783 earthquake. The purpose of this paper is to find further evidence of these earthquakes in Messina area by a multidisciplinary study aimed to recognize and date historical and paleo-earthquakes. For this goal we have analyzed historical, archaeological and geological information of excavations performed at Capo Peloro near the Torre del Faro village (Fig. 1) in the Torre degli Inglesi (English Tower), built on an abandoned Roman tower

A unique 4000 year long geological record of multiple tsunami inundations in the Augusta Bay (eastern Sicily, Italy)

We present the geological evidence for a 4000 year long record of multiple tsunami inundations along the coast of the Augusta Bay (eastern Sicily)and discuss its implications. The research was carried out through a multi-theme approach which benefited from an extraordinarily long historical record that we used to guide detailed geomorphologic and geologic surveys, coring campaigns and laboratory analyses. Two sites, named the Augusta Hospital and Priolo Reserve, were selected and investigated in detail along the 25 km-long coastline of Augusta Bay. We found evidence for six (possibly seven) tsunami deposits; three of them may be tentatively associated with the 1693 and 365 AD Ionian Sea historical tsunamis and the ~3600 BP Santorini event. The other three (possibly four) deposits are evidence for unknown paleo-inundations dated at about 650–770 AD, 600–400 BC and 975–800 BC (at Augusta Hospital site), and 800–600 BC (at Priolo Reserve site). We use these ages to extend further back the historical record of tsunamis available for this coastal area. The exceptional number of tsunami deposits found with this study allowed us to derive an average geologic tsunami recurrence interval in the Augusta Bay of about 600 years for the past 4 ka. Conversely, the historical tsunami data for the past millennium suggest an average tsunami recurrence interval of about 250 years. This difference in the average recurrence intervals suggests that only the strongest inundations may leave recognizable geological signatures at the investigated sites (i.e. the evidence for the 1908 and 1169 tsunamis is missing) but also that the geomorphological setting of the site and its erosional/depositional history are critical aspects for the data recording. Thus, an average recurrence interval derived from the geological record should be considered as a minimum figure. The identification and age estimation of tsunami deposits represent a new and independent contribution to tsunami scenarios and modeling for coastal hazard assessment in Civil Protection applications. Furthermore, our study cases provide new elements on tsunami deposit recognition related to exceptionally large events that occurred in the Aegean Sea

Identification of tsunami deposits in south-eastern Sicily: evidence for the 365 A.D. Crete earthquake?

In the past decade, the methodologies and techniques of paleoseismological studies have evolved towards a multidisciplinary approach for the characterization of past earthquakes. Along with traditional geologic and geomorphologic near-fault investigations, off-fault studies of evidence for past earthquakes, such as soft sediment deformation (e.g. Moretti, 2000; Marco and Agnon, 2005), evidence of liquefaction (e.g. Tuttle et al., 2002; Guarnieri et al., 2009) and tsunami deposits (Dawson and Stewart, 2007; Pantosti et al., 2008; De Martini et al., 2009) are considered useful tools in the assessment of paleoearthquakes ages, magnitudes, and earthquake recurrence rates. We present the preliminary results of off-fault paleoseismological studies carried out in south-eastern Sicily, focused to identify evidence of tsunami inundations

Liquefaction structures induced by historical earthquakes along the Ionian coast of Sicily (southern Italy)

The aim of this work is to present geological evidence of liquefactions triggered by earthquakes in eastern-Sicily and to analyze their characteristics. Liquefaction prone areas have been selected on the basis of the historical observations and by using aerial photographs, geological maps and field investigations.Though the difficulties caused by the intense human activity (urban settlement, industrial development, fluvial regimentation etc.), field investigations allowed us to recognize evidence of 2 liquefaction at several sites in the eastern flank of Mt. Etna and in the Catania plain to the south, where these phenomena are described by historical reports. In two sites we analyzed in details artificial exposures showing evidences of liquefaction features in the outcropping Holocene deposits: (1) the Minissale trench, in the Mascali area, and (2) the Agnone trench, in the Catania plain both placed onto the Gela foredeep

Imaging the structural style of an active normal fault through multidisciplinary geophysical investigation: a case study from the Mw 6.1, 2009 L'Aquila earthquake region (central Italy)

The normal fault-system responsible of the 2009 Mw 6.1 L'Aquila earthquake (Paganica-San Demetrio fault-system) comprises several narrow, fault-parallel valleys of controversial origin. We investigated a key section of the southeastern portion of this fault network along the small Verupola Valley. In order to characterize its nature and possible tectonic activity, we applied multiple-geosciences techniques able to image at depth the structure associated to this peculiar landform. We integrated magnetometry, 2-D P wave and resistivity tomography, surface waves and seismic noise analysis coupled with field mapping, shallow boreholes and trenching. According to our results, the Verupola Valley is a ∼30–40-m-deep graben controlled by a SW-dipping master fault and synthetic splays paired with an antithetic NE-dipping fault. The SW-dipping splays are active and cut very shallow (<2 m deep) Late Pleistocene sediments. The small amount of cumulated vertical offset (∼15 m) across the conjugated system may indicate a young fault inception or very low Quaternary slip-rates. Due to its structural continuity with the adjacent mapped strands of the Paganica–San Demetrio fault network, we relate the Verupola Valley to the recent activity of the southeastern segment of this fault system. We also suggest that other fault-parallel valleys can have the same tectonic origin and setting of the Verupola Valley. This latter represents a scale-independent analogue from metric scale (exposed in the palaeoseismological trenches) to the Middle Aterno Basin scale (seen from seismic profiles and fault mapping). Overall, the imaged structural style is coherent with the regional tectonic setting due to Quaternary crustal extension

In search of tsunami deposits along the eastern coast of Sicily (Italy): the state of the art

Eastern Sicily has been affected in historical times by large earthquakes followed by devastating tsunamis, such as the 1169, 1693 and 1908 events. In order to provide a long term assessment for tsunami recurrence and related hazard, we developed a multi-disciplinary study, with a paleoseismological approach, aimed to recognize and date historical and paleo-tsunami deposits. Starting from information on the effects of known tsunamis (hit localities, inundation areas, run-up heights) and with a geomorphological approach, we selected several sites, such as coastal lakes, marshes and lagoons, potentially suitable for preserving tsunami deposits. In these sites 64 test gouge cores have been dug by hand and engine coring. In order to reconstruct paleoenvironments and to identify potential paleo-tsunami deposits, sedimentological and paleontological analyses were carried out. Magnetic and X-ray analyses were used to highlight susceptibility variations and peculiar small-scale sedimentary structures not detectable trough the standard stratigraphic analysis. Moreover, radiocarbon dating and tephra identification provide age ranges of the tsunami deposits and constrains for sedimentation rates allowing the correlation with historical events. At Capo Peloro in north-eastern Sicily, combining archaeological, historical, and C14 data, we associated two tsunami deposits, to the 1783 and 17 A.D. earthquakes. We collected also evidence for the occurrence of multiple inundations at sites in the eastern flank of Mt Etna: three events in the past 580 yr at Anguillara site and four events in the past 4000 yr at Gurna site. In south-eastern Sicily, in the Augusta bay, combining historical, tephrostratigraphical and C14 dating, we reconstructed a tsunami inundation history composed of six events in the past 4000 yr, the two most recent ones are related to the 1693 and 1169 earthquakes

Geological reconstruction in the area of maximum co-seismic subsidence during the 2009 Mw=6.1 L’Aquila earthquake using geophysical analyses and borehole stratigraphy.

InSAR images showed that the 2009 Mw=6.1 normal faulting L'Aquila earthquake (Abruzzi region, central Italy) produced a maximum co-seismic subsidence of ca. 24 cm in the epicentral area. We report new results about the stratigraphic architecture of this area by means of the integration of geophysical and stratigraphic data from a new 151 m deep borehole. According to the indication of preliminary geophysical (electrical resistivity tomography and seismic noise) surveys, the borehole was drilled where maximum thicknesses of fine-grained sediments were expected. The geophysical results were also useful to estimate the basin substrate depth and to define the geometry of the continental deposits, successively constrained by the core stratigraphy. The core is characterized by two sequences separated by an erosional discontinuity. The upper sequence is composed by silty, sandy and gravelly deposits, mainly characterized by high values of electrical resistivity. The lower sequence is characterized by prevalence of grey clayey silt and sandy sediments, with low values of resistivity. Based on correlations among the stratigraphic core and outcrop data of the Aterno Valley, we interpret the upper sequence as related to fluvial-alluvial depositional environment during Middle Pleistocene-Holocene, whereas the lower sequence is related to deposition in a prevalent marshy floodplain environment during Early Pleistocene.Published350-3621A. Geomagnetismo e PaleomagnetismoJCR Journalrestricte

Identification of paleotsunami deposits in the Augusta Bay area (eastern Sicily, Italy): paleoseismological implication

In this paper we present the geological evidence of paleotsunamis in the Augusta area together with some paleoseismological implication derived from the discovery of multiple inundation events. It is well known that eastern Sicily has been affected in historical time by large earthquakes (CPTI Working group, 2004) and its southern sector in particular was strongly hit by the 1693 and 1169 events that were followed by devastating tsunamis. The Augusta Bay area is one of the locations where the information available from historical reports on tsunami effects (hit localities, inundated areas and run-up distribution) stimulated our curiosity in searching for the geological signature of tsunamis. The research was carried out through a multi-theme approach consisting of historical studies, geomorphological and geological surveys, coring campaigns, laboratory analyses (paleontological, radiometric, SEM, X-Ray, susceptibility, tephra, etc.)