Landslide susceptibility modeling assisted by Persistent Scatterers Interferometry (PSI): an example from the northwestern coast of Malta     

Piacentini  Daniela  Devoto  Stefano  Mantovani  Matteo  Pasuto  Alessandro  Prampolini  Mariacristina  Soldati  Mauro 《Natural Hazards》2015,78(1):681-697

Natural Hazards - Persistent Scatterers Interferometry (PSI) techniques are widely employed in geosciences to detect and monitor landslides with high accuracy over large areas, but they also suffer...  相似文献   

Modelling feedback from stars and black holes in galaxy mergers   总被引：2，自引：0，他引：2  

Volker Springel  Tiziana Di Matteo  Lars Hernquist 《Monthly notices of the Royal Astronomical Society》2005,361(3):776-794

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Biogeochemical processes involving dissolved CO2 and CH4 at Albano, Averno, and Monticchio meromictic volcanic lakes (Central–Southern Italy)     

Jacopo Cabassi  Franco Tassi  Orlando Vaselli  Jens Fiebig  Matteo Nocentini  Francesco Capecchiacci  Dmitri Rouwet  Gabriele Bicocchi 《Bulletin of Volcanology》2013,75(1):1-19

This paper focuses on the chemical and isotopic features of dissolved gases (CH₄ and CO₂) from four meromictic lakes hosted in volcanic systems of Central–Southern Italy: Lake Albano (Alban Hills), Lake Averno (Phlegrean Fields), and Monticchio Grande and Piccolo lakes (Mt. Vulture). Deep waters in these lakes are characterized by the presence of a significant reservoir of extra-atmospheric dissolved gases mainly consisting of CH₄ and CO₂. The δ¹³C-CH₄ and δD-CH₄ values of dissolved gas samples from the maximum depths of the investigated lakes (from ?66.8 to ?55.6?‰ V-PDB and from ?279 to ?195?‰ V-SMOW, respectively) suggest that CH₄ is mainly produced by microbial activity. The δ¹³C-CO₂ values of Lake Grande, Lake Piccolo, and Lake Albano (ranging from ?5.8 to ?0.4?‰ V-PDB) indicate a significant CO₂ contribution from sublacustrine vents originating from (1) mantle degassing and (2) thermometamorphic reactions involving limestone, i.e., the same CO₂ source feeding the regional thermal and cold CO₂-rich fluid emissions. In contrast, the relatively low δ¹³C-CO₂ values (from ?13.4 to ?8.2?‰ V-PDB) of Lake Averno indicate a prevalent organic CO₂. Chemical and isotopic compositions of dissolved CO₂ and CH₄ at different depths are mainly depending on (1) CO₂ inputs from external sources (hydrothermal and/or anthropogenic); (2) CO₂–CH₄ isotopic exchange; and (3) methanogenic and methanotrophic activity. In the epilimnion, vertical water mixing, free oxygen availability, and photosynthesis cause the dramatic decrease of both CO₂ and CH₄ concentrations. In the hypolimnion, where the δ¹³C-CO₂ values progressively increase with depth and the δ¹³C-CH₄ values show an opposite trend, biogenic CO₂ production from CH₄ using different electron donor species, such as sulfate, tend to counteract the methanogenesis process whose efficiency achieves its climax at the water–bottom sediment interface. Theoretical values, calculated on the basis of δ¹³C-CO₂ values, and measured δ¹³C_TDIC values are not consistent, indicating that CO₂ and the main carbon-bearing ion species (HCO₃ ^?) are not in isotopic equilibrium, likely due to the fast kinetics of biochemical processes involving both CO₂ and CH₄. This study demonstrates that the vertical patterns of the CO₂/CH₄ ratio and of δ¹³C-CO₂ and δ¹³C-CH₄ are to be regarded as promising tools to detect perturbations, related to different causes, such as changes in the CO₂ input from sublacustrine springs, that may affect aerobic and anaerobic layers of meromictic volcanic lakes.  相似文献   

A new hydrostratigraphic model of Venice area (Italy)   总被引：3，自引：3，他引：0  

Matteo Cultrera  Renzo Antonelli  Giordano Teza  Silvia Castellaro 《Environmental Earth Sciences》2012,66(4):1021-1030

Two environmental problems affect the Venice area: subsidence, which has been increasing due to the intensive water abstraction after the Second World War, and contamination of the soil and shallow aquifers. In order to address these problems, which are decisive factors in the entire Venetian ecosystem, the aquifer structure must be known in detail. The lithologic data are abundant and of good quality up to a depth of 50 m, whereas boreholes beyond this depth are much rarer and more dispersed, making their associated lithological data unreliable. This work, which uses the available data together with fast and low cost passive seismic measurements, provides an improved understanding of the deeper hydrogeologic domain. For this purpose, a MATLAB package (Modalstrata) has been developed to improve the correlation of the stratigraphic succession for each selected homogeneous sub-area and applied to obtain a new, upgraded hydrostratigraphic model. The horizontal to vertical spectral ratio passive seismic surveys have confirmed the lateral correlations among the sample areas at least for the two main aquifer horizons. Analysis and comparisons of several previous studies performed on the data related to the only drilling continuous coring 951 m deep in the Tronchetto Island (Venice), have allowed a satisfactory validation of the proposed hydrogeological model.  相似文献   

Origin of crystal-poor, differentiated magmas: insights from thermal gradient experiments     

Matteo Masotta  Carmela Freda  Mario Gaeta 《Contributions to Mineralogy and Petrology》2012,163(1):49-65

Crystal-poor, differentiated magmas are commonly erupted from shallow, thermally zoned magma chambers. In order to constrain the origin of these magmas, we have experimentally investigated crystallization, differentiation and crystal-melt separation in presence of a thermal gradient. Experiments have been designed taking advantage of the innate temperature gradient of the piston cylinder apparatus and carried out on a phonolitic system at 0.3 GPa and temperature ranging from 1,050 to 800°C. Crystallization degree and melt composition in experimental products vary as a function of the temperature gradient. In particular, melt composition differentiates from tephri-phonolite (starting material) to phonolite moving from the hotter, glassy zone (T ≤ 1,050°C) towards the cooler, heterogeneously crystallized zone (T ≤ 900°C) of the charge. The heterogeneously crystallized zone is made up of: (1) a crystal-rich, mushy region (crystallinity >30 vol%), (2) a rigid crystal framework (crystallinity ≤80 vol%) and (3) glassy belts of phonolitic glass at the top. Thermal gradient experiments picture crystallization, differentiation and crystal-melt separation processes occurring in a thermally zoned environment and reveal that relatively large volumes of crystal-poor melt (glassy belts) can originate as a consequence of the instability and collapse of the rigid crystal framework. Analogously, in thermally zoned magma chambers, the development and collapse of a solidification front may represent the controlling mechanism originating large volumes of crystal-poor, differentiated magmas.  相似文献   

Drainage network geometry versus tectonics in the Argentera Massif (French–Italian Alps)     

Adriano Ribolini  Matteo Spagnolo   《Geomorphology》2008,93(3-4):253-266

The Argentera Massif (French–Italian Alps), with its uniform lithology, was selected to evaluate how known Plio–Pleistocene tectonics have conditioned the drainage network geometry. The drainage network was automatically derived and ordered from a 10 m-resolution DEM. On hillshade images, alignments of morphological features were identified. The Massif was subdivided into 22 domains of 50 km² within which the directions of every river channel segment and the direction of the aligned morphological features were compared and contrasted with the strike of tectonic structures measured in the field. Results suggest that the Argentera drainage system is variously controlled by recent tectonics, depending on the Massif sector taken into account. In the NW sector, the vertical uplift is less because the strain has been accommodated in an oblique direction along a lateral thrust. In the SE sector, strain in a predominantly vertical direction along a frontal thrust has resulted in a major vertical displacement. Accordingly, the NW sector is characterized by (i) a strong geometric relationship between the main tectonic structures and the directions of river channels, (ii) longitudinal main rivers bordering the Massif, and (iii) a general trellis pattern within the domains.In the SE sector, the prolonged uplift has forced an original longitudinal drainage system to develop as a transverse system. This change has occurred by means of fluvial captures that have been identified by the presence of windgaps, fluvial elbows and knickpoints. At the domain scale, intense uplift of the SE sector has prompted the drainage pattern to evolve as a dendritic type with no clear influence of structure in the channel orientations.  相似文献   

Site characterization by seismic noise in Istanbul,Turkey     

Matteo Picozzi  Angelo Strollo  Stefano Parolai  Eser Durukal  Oguz Özel  Savas Karabulut  Jochen Zschau  Mustafa Erdik 《Soil Dynamics and Earthquake Engineering》2009

Single station seismic noise measurements were carried out at 192 sites in the western part of Istanbul, Turkey. This extensive survey allowed the fundamental resonance frequency of the sedimentary cover to be mapped, and identify areas prone to site amplification. The results are in good agreement with the geological distribution of sedimentary units, indicating a progressive decrease of the fundamental resonance frequencies from the northeastern part, where the bedrock outcrops, towards the southwestern side, where a thickness of some hundreds meters for the sedimentary cover is estimated. The particular distribution of fundamental resonance frequencies indicates that local amplification of the ground motion might play a significative role in explaining the anomalous damage distribution after the 17 August 1999 Kocaeli Earthquake.  相似文献   

Reconstruction and analysis of two long-term precipitation time series: Alpe Devero and Domodossola (Italian Western Alps)     

Guido Nigrelli  Matteo Collimedaglia 《Theoretical and Applied Climatology》2012,109(3-4):397-405

With this study, we analyzed two long-term precipitation time series recorded at Alpe Devero and Domodossola (Italian Western Alps) for two periods (1916–2010 and 1872–2010, respectively). The aims of the study were: to create the first precipitation time series covering more than 50?years for Alpe Devero, to extend and update the precipitation time series for Domodossola, to detect changes by means of trend analysis on the precipitation time series. After an accurate analysis of the metadata and the measurements recorded at each station, a trend analysis was performed on both datasets. The results showed a statistically significant decline in winter, summer, and annual precipitation at Alpe Devero and a nonsignificant decrease in seasonal and annual precipitation at Domodossola. Covering more than 90?years, the long-term precipitation time series at Alpe Devero and Domodossola represent unique data sets for this sector of Italian Western Alps. Continuing updating of the data could provide a useful resource for climate change studies in this area and, within a wider perspective, in Alpine regions.  相似文献   

Disperse Two-Phase Flows,with Applications to Geophysical Problems     

Luigi C. Berselli  Matteo Cerminara  Traian Iliescu 《Pure and Applied Geophysics》2015,172(1):181-196

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A User-Oriented Methodology for DInSAR Time Series Analysis and Interpretation: Landslides and Subsidence Case Studies     

Davide Notti  Fabiana Calò  Francesca Cigna  Michele Manunta  Gerardo Herrera  Matteo Berti  Claudia Meisina  Deodato Tapete  Francesco Zucca 《Pure and Applied Geophysics》2015,172(11):3081-3105

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