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651.
Manuel M. González‐Duarte Cesar Megina Doris De Vito Cristina Goia Di Camillo Stefania Puce Stefano Piraino 《Marine Ecology》2016,37(1):155-163
Hydroids are important components of the communities of rocky bottom shallow coastal areas. The hydrozoan fauna of the Mediterranean Sea is probably one of most investigated in the world, with lots of faunistic and biogeographical studies. However, quantitative studies using the same sampling methodology and controlled sampling effort have been restricted to areas in the Western and Central Mediterranean. We compared hydroid assemblages in four areas of the Mediterranean Sea, from the Gulf of Cádiz to the South Adriatic Sea, following the same sampling and quantification methodology. Our analysis showed the dominant Atlantic character of the assemblages of the Gulf of Cádiz and the South Alboran Sea because of the influence of the inflowing Atlantic waters. Conversely, the hydroid assemblages of the North Alboran Sea were more similar to the assemblages in the Ligurian and in the South Adriatic, and with a number of species ranking between the observed in these two Mediterranean zones. Fourteen species were identified as making the most significant contributions to characterizing the Mediterranean hydroid species pool from a quantitative point of view. These taxa include species previously named as typical components of the Mediterranean hydroid fauna as well as those only recently recorded in the region (Eudendrium moulouyensis) and invaders such as Clytia hummelincki. 相似文献
652.
In this paper a new kinematic and dynamic model on the Recent and active contractional deformation of the Catania region, eastern Sicily, is discussed. The study area represents one of the most seismically active region of the Mediterranean, located at the intersection between the front of the Sicily collision belt and the seismogenic Siculo-Calabrian Rift-Zone. The analysed contractional tectonics form an active triangle zone that originated from the tectonic inversion of a Lower-Middle Pleistocene extensional basin, which was located at the northern edge of the African foreland. The triangle zone consists of two antithetic ENE–WSW oriented thrust-ramps that show evidence of motion during the Holocene and bound a folded belt that involves alluvial deposits as young as 40 ka. These contractional structures represent the final product of the positive tectonic inversion of extensional features located, in the Hyblean Plateau in SE Sicily, along the flank of the active rift zone. The Late Quaternary motions along the inverted structures was accommodated to the west by a major N–S oriented left-lateral fault zone, which separates the active contractional domains from the adjacent sectors of the African margin. As a whole, the Late Quaternary contractional tectonics of SE Sicily have been related to a NW-verging crustal stacking, related to a Mantle intrusion beneath the Hyblean Plateau that developed as effect of the rift-flank deformation. The crustal lineaments, which compose the new kinematic model, represents potentially active seismogenic sources that might be considered in the frame of the seismotectonic picture of the Catania region. 相似文献
653.
654.
Teresa Salvatici Stefano Morelli Veronica Pazzi William Frodella Riccardo Fanti 《山地科学学报》2017,14(4):636-648
On 4th November 2010, a debris flow detached from a large debris cover accumulated above the lowermost portion of the Rotolon landslide (Vicentine Pre-Alps, NE Italy) and channelized in the valley below within the Rotolon Creek riverbed. Such event evolved into a highly mobile and sudden debris flow, damaging some hydraulic works and putting at high risk four villages located along the creek banks. A monitoring campaign was carried out by means of a ground based radar interferometer (GB-InSAR) to evaluate any residual displacement risk in the affected area and in the undisturbed neighbouring materials. Moreover, starting from the current slope condition, a landslide runout numerical modelling was performed by means of DAN-3D code to assess the impacted areas, flow velocity, and deposit distribution of the simulated events. The rheological parameters necessary for an accurate modelling were obtained through the back analysis of the 2010 debris flow event. Back analysis was calibrated with all of the available terrain data coming from field surveys and ancillary documents, such as topographic, geomorphological and geological maps, with pre- and post-event LiDAR derived DTMs, and with orthophotos. Finally, to identify new possible future debris flow source areas as input data for the new modelling, all the obtained terrain data were reanalysed and integrated with the GB-InSAR displacement maps; consequently, new simulations were made to forecast future events. The results show that the integration of the selected modelling technique with ancillary data and radar displacement maps can be a very useful tool for managing problems related to debris flow events in the examined area. 相似文献
655.
Emilio Cuoco Giuseppe Verrengia Stefano De Francesco Dario Tedesco 《Environmental Earth Sciences》2010,61(3):525-538
This is the first hydro-geochemical investigation carried out on the Roccamonfina Volcanic Complex groundwaters. The chemistry of Roccamonfina waters is defined by water–rock and water–rock–gas interactions. In fact, interactions between rocks of the first eruptive high-K formations and circulating groundwaters are recognized by high K concentrations. On the other hand, inverse concentration of calcium versus alkali metals is related to two different rock interactions occurring in different areas of the volcano: (a) within the caldera where groundwaters flow within latite and pyroclastic formations releasing calcium, and (b) similarly at the base of the volcano where groundwaters flowing from surrounding carbonates got strongly enriched in Ca. These geochemical processes are also associated with K (SE of caldera) and Mg/Ca (in sites located at the NE base of the volcano) decrease. Completely different dynamics occurs at Riardo groundwaters (SE). Here waters are the result of a mix between the Roccamonfina deep aquifer and the carbonate aquifer of the Riardo plain. Rich-CO2 emissions make these waters strongly mineralized. Minor elements show a similar geochemical behavior of major ions and are crucial defining interactions processes. The evolution of Roccamonfina groundwaters is also evident along the simultaneous enrichment of Ba, Sr, and Ca. Ba increase is the result of deep local carbonate alteration enhanced by CO2 emissions and, the lower Sr/Ca ratio, from 10 to 2 (ppb/ppm), is also due to the same process. In the light of our results the Roccamonfina aquifer can be schematically divided into two main reservoirs: (a) a superficial aquifer which basically follows the volcanic structure morphology and tectonics and (b) a deeper reservoir, originating within the oldest Roccamonfina volcano ultra potassic lavas and then flowing into the carbonate aquifers of the neighboring plain. Eventually, the chemistry of the Roccamonfina aquifer does not show any specific and visible pollution, contrary to what happens in the volcano surrounding plains. In fact, only 14% of the samples we collected (206) show a NO3 content >30 mg/l. These sites are all located at the base of the volcano, near the plain. 相似文献
656.
Paolo Mazzetti Giuseppe Puglisi Luca D’Auria Roberto Roncella Danilo Reitano Riccardo Merenda Stefano Nativi 《Earth Science Informatics》2017,10(4):443-455
This paper presents the Virtual Research Environment (VRE) enabling two European GEO Geohazard Supersites in Italy. According to GEO (Group on Earth Observation) vision, Geohazard Supersites provide access to spaceborne and in-situ geophysical data and models for selected sites prone to natural hazards –noticeably, earthquakes and volcano eruptions. The VRE was implemented in the framework of the Mediterranean Supersite Volcanoes (MED-SUV) project, funded by the European Commission. MED-SUV realized one of the European supersite demonstrators covering the two Permanent Supersites selected in Italy: Mt. Etna and Campi Flegrei/Vesuvius. The MED-SUV VRE provides advanced services for heterogeneous data and information management and sharing. MED-SUV started identifying the main supersite requirements including: the interoperability with existing data/information supply systems, the support of policy-based access control, the access to processing capabilities provided by external platforms, the management resources for publishing and sharing new products, the integration with significant global systems such as GEOSS and EPOS. MED-SUV adopted a System of Systems (SoS) approach to address interoperability with the identified heterogeneous systems supplying data and information. The SoS approach is based on a brokering architecture, where a specialized component (i.e the MED-SUV Broker: MSB) connects the existing and next-coming data sources leaving them autonomous. MSB carries out all the necessary mediation and harmonization tasks exposing standard interfaces enabling the interconnection with external systems like GEOSS and EPOS. In addition, MSB is accessible via a JavaScript library implementing Web APIs to facilitate the development of Web and mobile applications. 相似文献
657.
Elenio Avolio Fabio Orlandi Carlo Bellecci Marco Fornaciari Stefano Federico 《Theoretical and Applied Climatology》2012,107(3-4):531-540
In phenological studies, plant development and its relationship with meteorological conditions are considered in order to investigate the influence of climatic changes on the characteristics of many crop species. In this work, the impact of climate change on the flowering of the olive tree (Olea europaea L.) in Calabria, southern Italy, has been studied. Olive is one of the most important plant species in the Mediterranean area and, at the same time, Calabria is one of the most representative regions of this area, both geographically and climatically. The work is divided into two main research activities. First, the behaviour of olive tree in Calabria and the influence of temperature on phenological phases of this crop are investigated. An aerobiological method is used to determine the olive flowering dates through the analysis of pollen data collected in three experimental fields for an 11-year study period (1999–2009). Second, the study of climate change in Calabria at high spatial and temporal resolution is performed. A dynamical downscaling procedure is applied for the regionalization of large-scale climate analysis derived from general circulation models for two representative climatic periods (1981–2000 and 2081–2100); the A2 IPCC scenario is used for future climate projections. The final part of this work is the integration of the results of the two research activities to predict the olive flowering variation for the future climatic conditions. In agreement with our previous works, we found a significant correlation between the phenological phases and temperature. For the twenty-first century, an advance of pollen season in Calabria of about 9?days, on average, is expected for each degree of temperature rise. From phenological model results, on the basis of future climate predictions over Calabria, an anticipation of maximum olive flowering between 10 and 34?days is expected, depending on the area. The results of this work are useful for adaptation and mitigation strategies, and for making concrete assessments about biological and environmental changes. 相似文献
658.
Results from visual sightings of large floating debris are presented, taken in the Ligurian Sea, a sub-basin of the north-western Mediterranean Sea which belongs to the recently stated "Cetacean Sanctuary". Data have been collected during three oceanographic cruises, during the summer of 1997 and 2000. Results for the 1997 data suggest a debris density of the order of 15-25 objects km(-2), while for the 2000 data, a lower density of the order of 3-1.5 objects km(-2) is found. The difference between the two results appears statistically significant using simple tests. Possible reasons for the observed variability are discussed, including meteorological forcing, marine currents and debris input variability. 相似文献
659.
The lethal and sublethal effects of the xenoestrogen 4-nonylphenol (NP) were evaluated in the cockle Cerastoderma glaucum. In a 96-h lethality test, bivalves were exposed to 0, 0+ acetone, 0.19, 0.38, 0.75, 1.5 and 3.0 mg NP/l. The 96-h LC(50) value was 0.3mg NP/l. No mortality was observed at 0.1 mg NP/l. The potential estrogenicity of NP was studied in both sexually undifferentiated (resting phase) and differentiated (pre-spawning phase) cockles, exposed for 7 and 14 days to 0, 0+ acetone, 0.0125, 0.025, 0.05, and 0.1 mg NP/l. Vitellogenin (Vg)-like protein levels were determined in both haemolymph and digestive gland by the alkali-labile phosphate (ALP) assay. In the resting phase, exposure for 7 days to 0.1 mg NP/l resulted in significant increases in ALP in both haemolymph and digestive gland, compared with controls. A significant increase was also observed in digestive gland of animals exposed to 0.0125 mg NP/l-exposed animals. After 14 days of exposure, haemolymph ALP levels were significantly increased in exposed animals at all NP concentrations tested, whereas no difference was recorded in digestive gland. In the pre-spawning phase, exposure for 7 days to NP significantly increased ALP levels in haemolymph from males exposed at all NP concentrations tested, whereas no significant variations were found in haemolymph from females. NP (0.05 and 0.1 mg/l) was also shown to increase ALP concentrations significantly in digestive gland of males, but not in those of females. Likewise, after 14 days' exposure, ALP levels significantly increased in haemolymph from males only at 0.1 mg NP/l. Conversely, NP caused significant increases in ALP levels in digestive gland from both males (at all NP concentrations tested) and females (at 0.025 and 0.1 mg NP/l). These results demonstrate that NP induces Vg synthesis in C. glaucum. Interestingly, males were more responsive to NP than females. 相似文献
660.
Research studies on the damped cable system (DCS) for seismic protection of frame structures are presented in this paper and the accompanying one. This technology includes prestressed steel cables linked to pressurized fluid viscous spring‐dampers fixed to the foundation at their lower ends, and to the top floor, or one of the upper floors, at their upper ends. The cables have sliding contacts with the floor slabs, to which they are joined by steel deviators. The general characteristics of the system, as well as of the constituting spring‐dampers and cables, are initially discussed. The results of a laboratory testing campaign developed on a DCS prototype are examined, and transferred into the formulation of the finite element model of the system, conceived to be easily generated by commercial structural analysis programs. A second dynamic experimental investigation follows, concerning a pilot installation of the system on a full‐scale mock‐up building. The benefits of the protective technology are evaluated in terms of maximum displacements and accelerations, as well as of equivalent viscous damping coefficient and MDOF transmissibility ratio. Further sections of the study, including a preliminary sizing criterion of DCS, additional numerical enquiries aimed at optimizing its geometrical layout, and the application to a real case study building, are offered in the companion paper. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献