Evidence of a partial melt zone beneath Stromboli volcano (Italy) from inversion of teleseismic receiver functions     

Carmen Martinez-Arevalo  Carla Musumeci  Domenico Patanè 《地学学报》2009,21(5):386-392

Teleseismic body waves from broadband seismic stations are used to investigate the crustal and uppermost mantle structure of Stromboli volcano through inversion of the receiver functions (RFs). First, we computed RFs in the frequency domain using a multiple-taper spectral correlation technique. Then, the non-linear neighbourhood algorithm was applied to estimate the seismic shear wave velocity of the crust and uppermost mantle and to define the main seismic velocity discontinuities. The stability of the inversion solution was tested using a range of initial random seeds and model parameterizations. A shallow Moho, present at depth of 14.8 km, is evidence of a thinned crust beneath Stromboli volcano. However, the most intriguing and innovative result is a low S velocity layer in the uppermost mantle, below 32 km. The low S velocity layer suggests a possible partial melt region associated with the volcanism, as also recently supported by tomographic studies and petrological estimations.  相似文献   

L'angle de chute au sol de la grêle     

Domenico Vento 《大气与海洋》2013,51(1):81-85

Résumé

Cette étude présente des résultats expérimentaux sur les effets du vent et de l'échantillonnage sur la mesure de l'intensité des chutes de grêle, et suggère des thèmes de discus non pour l'Atelier.

L'angle moyen de chute des grêlons, mesuré à partir de la verticale, est un indice significatif de l'augmentation de l'énergie cinétique due à la vitesse du vent au sol. En Italie, au cours des années 1972–1975, 61% des observations révèlent un effet important des vents. Au cours d'un été de Grossversuch IV en Suisse, 41% des observations révèlent aussi de tels effets. Ces observations ont été faites à l’ aide de grêlimètres à cinq faces (hailcubes). On propose un plus grand effort pour rendre possible une estimation des effets du vent à l'aide de grélimètres horizontaux, peut être en utilisant, comme mesure principale, le rapport de la longueur sur la largeur des empreintes faites par les grêlons de la classe centrale de dimensions qui a touché les grêlimètres.

Des résultats sur des mesures juxtaposées du nombre de grêlons, par intervalle donnée de diamètres, et d'énergie cinétique sont aussi présentées. Ces mesures soulignent les erreurs dues à l'échantillonnage qui peuvent être considérables, spécialement pour les gros grêlons naturellement moins nombreux.  相似文献   

First <Superscript>13</Superscript>C/<Superscript>12</Superscript>C isotopic characterisation of volcanic plume CO<Subscript>2</Subscript>     

Giovanni Chiodini  Stefano Caliro  Alessandro Aiuppa  Rosario Avino  Domenico Granieri  Roberto Moretti  Francesco Parello 《Bulletin of Volcanology》2011,73(5):531-542

We describe analytical details and uncertainty evaluation of a simple technique for the measurement of the carbon isotopic composition of CO₂ in volcanic plumes. Data collected at Solfatara and Vulcano, where plumes are fed by fumaroles which are accessible for direct sampling, were first used to validate the technique. For both volcanoes, the plume-derived carbon isotopic compositions are in good agreement with the fumarolic compositions, thus providing confidence on the method, and allowing its application at volcanoes where the volcanic component is inaccessible to direct sampling. As a notable example, we applied the same method to Mount Etna where we derived a δ¹³C of volcanic CO₂ between −0.9 ± 0.27‰ and −1.41 ± 0.27‰ (Bocca Nuova and Voragine craters). The comparison of our measurements to data reported in previous work highlights a temporal trend of systematic increase of δ¹³C values of Etna CO₂ from ~ −4‰, in the 1970’s and the 1980’s, to ~ −1‰ at the present time (2009). This shift toward more positive δ¹³C values matches a concurrent change in magma composition and an increase in the eruption frequency and energy. We discuss such variations in terms of two possible processes: magma carbonate assimilation and carbon isotopic fractionation due to magma degassing along the Etna plumbing system. Finally, our results highlight potential of systematic measurements of the carbon isotopic composition of the CO₂ emitted by volcanic plumes for a better understanding of volcanic processes and for improved surveillance of volcanic activity.  相似文献   

Investigation of rock-to-water release and fate of major,minor, and trace elements in the metabasalt–serpentinite shallow aquifer of Mt. Reventino (CZ,Italy) by reaction path modelling     

Carmine Apollaro  Luigi Marini  Teresa Critelli  Donatella Barca  Andrea Bloise  Rosanna De Rosa  Francesca Liberi  Domenico Miriello 《Applied Geochemistry》2011,26(9-10):1722-1740

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An analysis of debris-flow events in the Sardinia Island (Thyrrenian Sea, Italy)   总被引：1，自引：1，他引：0  

Laura Turconi  Sunil Kumar De  Francesca Demurtas  Luca Demurtas  Bruna Pendugiu  Domenico Tropeano  Gabriele Savio 《Environmental Earth Sciences》2013,69(5):1509-1521

On 6 December 2004, the Villagrande Strisaili area (middle-east Sardinia), was struck by debris flows; 330 mm of rainfall took place within 3 h with an hourly intensity of 120 mm, which is far more above than normal for the study area. In the urban center stony and driftwood deposits accounted for a total volume estimated as 10,000 m³. The event claimed huge amount of infrastructural loss and two human lives. According to the chronicle reports, the area experienced two debris-flow events in the last century. The present paper is the outcome of an intensive study of such debris-flow events including their physical processes and geomorphological effects through both field survey and laboratory analysis.  相似文献   

Towards a Flux-Partitioning Procedure Based on the Direct Use of High-Frequency Eddy-Covariance Data     

Luigi Palatella  Gianfranco Rana  Domenico Vitale 《Boundary-Layer Meteorology》2014,153(2):327-337

Scanlon and Sahu (Water Resour Res 44(10):W10418, 2008) proposed an interesting method to estimate assimilation, respiration, evaporation and transpiration directly using high-frequency eddy-covariance measurements. In this note we critically revise this method and, in particular, using the Descartes’ rule of sign, we show that one branch of solutions can be directly neglected reducing the analytical complexity of the procedure. We also discuss the stability of the results of the method with respect to the input parameters, especially to the water-use efficiency.  相似文献   

Event Scenario Analysis for the Design of Rockslide Countermeasures   总被引：2，自引：0，他引：2  

GIGLI Giovanni  INTRIERI Emanuele  LOMBARDI Luca  NOCENTINI Massimiliano  FRODELLA William  BALDUCCI Marco  VENANTI Luca Domenico  CASAGLI Nicola 《山地科学学报》2014,(6):1521-1530

The Torgiovannetto quarry（Assisi municipality,central Italy） is an example of a site where the natural equilibrium was altered by human activity,causing current slope instability phenomena which threaten two roadways important for the local transportation.The quarry front,having a height of about 140 m,is affected by a 182,000 m3 rockslide developed in intensely fractured limestone and is too large to be stabilized.In 2003 some tension cracks were detected in the vegetated area above the quarry upper sector.From then on,several monitoring campaigns were carried out by means of different instrumentations（topographic total station,extensometers,inclinometers,ground-based interferometric radar,laser scanner and infrared thermal camera）,allowing researchers to accurately define the landslide area and volume.The latter’s major displacements are localized in the eastern sector.The deformational field appears to be related to the seasonal rainfall.The landslide hazard associated with the worst case scenario was evaluated in terms of magnitude,intensity and triggering mechanism.For the definition of the possible runout process the DAN 3D code was employed.The simulation results were used in order to design and construct a retaining embankment.Furthermore,in order to preserve both the safety of the personnelinvolved in its realization and of the roadways users,an early warning system was implemented.The early warning system is based on daily-averaged displacement velocity thresholds.The alarm level is reached if the prediction based on the methods of Saito（1969） and Fukuzono（1985） forecasts an imminent rupture.  相似文献   

Trend of annual maximum rainfall in Campania region (Southern Italy)     

Angelo Avino  Salvatore Manfreda  Luigi Cimorelli  Domenico Pianese 《水文研究》2021,35(12):e14447

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Assimilation of historical head data to estimate spatial distributions of stream bed and aquifer hydraulic conductivity fields          下载免费PDF全文

Ayman H. Alzraiee  Ryan Bailey  Domenico Bau 《水文研究》2017,31(7):1527-1538

Management of water resources in alluvial aquifers relies mainly on understanding interactions between hydraulically connected streams and aquifers. Numerical models that simulate this interaction often are used as decision support tools for water resource management. However, the accuracy of numerical predictions relies heavily on unknown system parameters (e.g., streambed conductivity and aquifer hydraulic conductivity), which are spatially heterogeneous and difficult to measure directly. This paper employs an ensemble smoother to invert groundwater level measurements to jointly estimate spatially varying streambed and alluvial aquifer hydraulic conductivity along a 35.6‐km segment of the South Platte River in Northeastern Colorado. The accuracy of the inversion procedure is evaluated using a synthetic experiment and historical groundwater level measurements, with the latter constituting the novelty of this study in the inversion and validation of high‐resolution fields of streambed and aquifer conductivities. Results show that the estimated streambed conductivity field and aquifer conductivity field produce an acceptable agreement between observed and simulated groundwater levels and stream flow rates. The estimated parameter fields are also used to simulate the spatially varying flow exchange between the alluvial aquifer and the stream, which exhibits high spatial variability along the river reach with a maximum average monthly aquifer gain of about 2.3 m³/day and a maximum average monthly aquifer loss of 2.8 m³/day, per unit area of streambed (m²). These results demonstrate that data assimilation inversion provides a reliable and computationally affordable tool to estimate the spatial variability of streambed and aquifer conductivities at high resolution in real‐world systems.  相似文献   

Modal analysis of pile‐supported structures during seismic liquefaction          下载免费PDF全文

Domenico Lombardi  Subhamoy Bhattacharya 《地震工程与结构动力学》2014,43(1):119-138

The purpose of this paper is to investigate the effects of liquefaction on modal parameters (frequency and damping) of pile‐supported structures. Four physical models, consisting of two single piles and two 2 × 2 pile groups, were tested in a shaking table where the soil surrounding the pile liquefied because of seismic shaking. The experimental results showed that the natural frequency of pile‐supported structures may decrease considerably owing to the loss of lateral support offered by the soil to the pile. On the other hand, the damping ratio of structure may increase to values in excess of 20%. These findings have important design consequences: (a) for low‐period structures, substantial reduction of spectral acceleration is expected; (b) during and after liquefaction, the response of the system may be dictated by the interactions of multiple loadings, that is, horizontal, axial and overturning moment, which were negligible prior to liquefaction; and (c) with the onset of liquefaction due to increased flexibility of pile‐supported structure, larger spectral displacement may be expected, which in turn may enhance P‐delta effects and consequently amplification of overturning moment. Practical implications for pile design are discussed. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献