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   

Peculiar earthquake damage on a reinforced concrete building in San Gregorio (L��Aquila, Italy): site effects or building defects?     

Marco Mucciarelli  Marcello Bianca  Rocco Ditommaso  Marco Vona  Maria Rosaria Gallipoli  Alessandro Giocoli  Sabatino Piscitelli  Enzo Rizzo  Matteo Picozzi 《Bulletin of Earthquake Engineering》2011,9(3):825-840

In San Gregorio (L’Aquila, Italy) a three-story, reinforced concrete (RC) building had the first floor collapsed following the earthquake of April 6, 2009. The remaining two stories fell with a displacement in the horizontal projection of about 70 cm. This unusual behaviour is made more puzzling by the fact that buildings located at a short distance and with similar features had little or no damage reported. To understand the causes of the collapse we performed strong motion recordings, microtremor measurements, a detailed geological survey, a high-resolution geo-electrical tomography, a borehole with a down-hole test. On the building we performed a geometrical survey and laboratory tests on concrete cores. The acceleration and noise recordings have shown a high amplification with uphill-downhill direction. The geological survey has revealed the presence of co-seismic fractures on stiff soils. Geo-electrical tomography has shown an unexpected, strong discontinuity just below the building. Taking advantage of excavations in adjacent lots, we have highlighted rare cataclastic decimetric bands with a very low resistance material incorporated in well-stratified calcarenites. The same soft material has been founded in the borehole down to 17 m from ground level, showing a shear wave velocity that starts at 250 m/s, increases with depth and has an abrupt transition in calcarenites at 1,150 m/s. The surface geophysical measurements in the vicinity of the site have not shown similar situations, with flat HVSR curves as expected for a rock outcrop, except for a lateral extension of the soft zone. The analysis on the quality of the building materials has yielded values higher than average for the age and type of construction, and no special design or construction deficiencies have been observed. A strong, peculiar site effect thus appears to be the most likely cause of the damage observed.  相似文献   

Far field damage on RC buildings: the case study of Navelli during the L��Aquila (Italy) seismic sequence, 2009     

M. Mucciarelli  M. Bianca  R. Ditommaso  M. R. Gallipoli  A. Masi  C. Milkereit  S. Parolai  M. Picozzi  M. Vona 《Bulletin of Earthquake Engineering》2011,9(1):263-283

After the recent Central Italy Earthquake of the 6th April 2009 (Mw = 6.3), the Italian and German engineer and geophysicist Task Force carried out a wide characterization of sites, buildings and damages. In Navelli, a town about 35 km far from epicentre, heavy damage occurred on a reinforced concrete (RC) building that represent an anomalous case of damage, when compared with those occurred in the neighbouring area. In this paper, characterization of the site and damage of the Navelli RC Building is reported and discussed. We performed ambient noise and strong motion measurements, installing one three-directional accelerometer on each floor of the structure and two in free-field, and we have carried out repeated measurements using a couple of three-directional tromometers. In the mean time, a geological survey was carried out and the site response was investigated, with the aid of down-hole measurements. It was thus possible to investigate the structural response and damage taking into account site condition. One of the main results of this work is that repeating analyses using ambient noise measurements show that the main structural frequencies reached after the first damaging shock are constant over time, and then the structural behaviour appears stationary at long term. On the other hand, the strong motion recordings show that the building exhibits a transient non-stationary behaviour as the fundamental frequency changes during each aftershock, then returning to the starting value after each event.  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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