Local Circulation Diurnal Patterns and Their Relationship with Large-Scale Flows in a Coastal Area of the Tyrrhenian Sea   总被引：1，自引：0，他引：1  

Igor Petenko  Giangiuseppe Mastrantonio  Angelo Viola  Stefania Argentini  Lucia Coniglio  Paolo Monti  Giovanni Leuzzi 《Boundary-Layer Meteorology》2011,139(2):353-366

In order to characterise the local low-level circulation in the Tyrrhenian Sea coastal area near Rome, the wind field observed by conventional anemometers, Doppler sodar, and rawinsonde has been analysed. The prevailing diurnal behaviour of wind speed and direction as a function of season was highlighted, and the existence of two different patterns of the local circulation, mainly due to land and sea breezes and to the drainage flow from the mouth of the Tiber valley, revealed. The comparison between the low-level circulation and synoptic flow allowed us to determine the influence of the large-scale flow on nocturnal currents that are observed at the Pratica di Mare site and the way that wind direction evolves during the day. Numerical simulations are consistent with experimental data and depict the main features of the low-level wind field in the area.  相似文献   

Evaluation of site effects in the Aterno river valley (Central Italy) from aftershocks of the 2009 L��Aquila earthquake     

F. Bergamaschi  G. Cultrera  L. Luzi  R. M. Azzara  G. Ameri  P. Augliera  P. Bordoni  F. Cara  R. Cogliano  E. D��Alema  D. Di Giacomo  G. Di Giulio  A. Fodarella  G. Franceschina  F. Galadini  M. R. Gallipoli  S. Gori  P. Harabaglia  C. Ladina  S. Lovati  S. Marzorati  M. Massa  G. Milana  M. Mucciarelli  F. Pacor  S. Parolai  M. Picozzi  M. Pilz  S. Pucillo  R. Puglia  G. Riccio  M. Sobiesiak 《Bulletin of Earthquake Engineering》2011,9(3):697-715

A temporary network of 33 seismic stations was deployed in the area struck by the 6th April 2009, Mw 6.1 (Scognamiglio et?al. in Seism Res Lett 6/81, 2010), L??Aquila earthquake (central Italy), with the aim to investigate the site amplification within the Aterno river Valley. The seismograms of 18 earthquakes recorded by 14 of the 33 stations were used to evaluate the average horizontal to vertical spectral ratio (HVSR) for each site and the standard horizontal spectral ratio (SSR) between a site and a reference station. The obtained results have been compared to the geological and geophysical information in order to explain the resonance frequencies and the amplification levels with respect to surface geology of the valley. The results indicate that there is no uniform pattern of amplification, because of the complex geologic setting, as the thickness and degree of cementation of the deposits is highly variable.  相似文献   

Diagenetic and thermal history of the Jurassic-Tertiary succession of the Zagros Mountains in the Dezful Embayment (SW Iran): constraints from fluid inclusions     

A. Ceriani  R. Calabrò  A. Di Giulio  R. Buonaguro 《International Journal of Earth Sciences》2011,100(6):1265-1281

To constraint the diagenetic and thermal history in the Mesozoic-Tertiary succession of the Zagros Fold-Belt, a study was performed on fluid inclusions trapped in intergranular, vug, and fracture-filling cements in Jurassic to Miocene outcrop samples collected along the Anneh and Fahliyan Valleys of Khuzestan Province, southwest Iran. Petrographic observations showed at least two systems of fractures that postdate intergranular cementation. Two different types of oil-filled fluid inclusions occur in the intergranular cements and in the first fracture network, but they are absent in the second fracture network. Microthermometry of fluid inclusions was used to determine the temperature and salinity of fluids responsible for mineral precipitation. Within intergranular cements and calcite fillings the oldest fractures, precipitation occurred from high saline fluids in a temperature range of 60–120°C, depending on the stratigraphic depth. The strong correlation between fluid inclusions temperature and stratigraphic depth suggests that the intergranular cementation and the first fracture-filling event occurred prior to structural deformation. Furthermore, this correlation indicates a relatively constant paleogeothermal gradient at the time of cement precipitation of about 28°C/Km. On the contrary, fluid inclusions trapped in cements within the second fracture network lack oil and contain freshwater trapped at low temperatures that do not correlate to the stratigraphic position. This suggests second fracturing event occurred after oil migration and during or after deformation of the Zagros Fold-Belt, when the samples were in a near-surface position.  相似文献   

Flexural response of the Venetian foreland to the Southalpine tectonics along the TRANSALP profile     

C. Barbieri  G. Bertotti  A. Di Giulio  R. Fantoni  R. Zoetemeijer 《地学学报》2004,16(5):273-280

The Venetian Basin was affected by flexure related to the Southalpine shortening phase during the Middle Miocene – Early Pliocene. This downbending is quantified here using a two‐dimensional flexural model. A recently improved data set on basin geometry based on the bottom of the Serravallian–Tortonian clastic wedge, on palaeobathymetry and gravity anomalies is used to constrain the components of flexure and to test the importance of the initial bathymetry in evaluating the contribution of surface loads to deflection. A good fit is obtained assuming a northward broken plate configuration of the downbent Adriatic plate with an effective elastic thickness of 20 km. Results highlight that, in the studied region, flexure related to the Eastern Southern Alps is totally due to surface loads (topographic load partly replacing initial bathymetry) and that no hidden loads are required. Furthermore, the palaeobathymetry contributes up to 50% to the total flexure in the studied region.  相似文献   

Correlations between diffuse interstellar bands and atomic lines     

G. A. Galazutdinov  Giulio Manicò  Valerio Pirronello  Jacek Kre&#;owski 《Monthly notices of the Royal Astronomical Society》2004,355(1):169-177

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Xenotime-(Y) formation from zircon dissolution–precipitation and HREE fractionation: an example from a metamorphosed phosphatic sandstone,Espinhaço fold belt (Brazil)     

Gerhard Franz  Giulio Morteani  Dieter Rhede 《Contributions to Mineralogy and Petrology》2015,169(4):1-22

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Major,trace element and stable isotope composition of water and muds precipitated from the hot springs of Bolivia: Are the waters of the spring's potential ore forming fluids?     

Giulio Morteani  Peter Möller  Peter Dulski  Christine Preinfalk 《Chemie der Erde / Geochemistry》2014

The deposition of metal-rich black or reddish muds by many thermal springs in the Cordilleras and the Altiplano of Bolivia suggest that these geothermal waters may be related to those that once formed the world-class Bolivian tin, silver and gold mineralisation. The discharge temperatures of these springs are as high as 70 °C. According to δ¹⁸O, δD, tritium data and Ar/N₂ ratios these waters are predominantly of meteoric origin. Less than 10% of the discharging thermal water represents deep-seated metal-rich thermal brines of at least 530 °C according to carbon exchange between CO₂ and CH₄. These brines ascend along tectonic faults and mix with low-temperature meteoric water in surface-near aquifers. The meteoric component of the thermal water is recharged in the high Cordilleras with residence times exceeding 50 years. The chemical composition of the thermal water is dominated by the rather inefficient low-temperature leaching of the surface-near aquifer rocks by meteoric water. The small fraction of metal-rich hot deep-seated water is not able to increase the metal content of the water mix to a level sufficient to classify these thermal waters as ore-bearing. Surface-near leaching is supported, e.g., by the B/Li ratios of the spring water of the Western Cordillera and Caleras/Pulacayo in the Eastern Cordillera that correspond very closely to that of the easily leachable glassy inclusions of the outcropping andesitic lavas. The often remarkable metal content of the muds deposited by the springs originate from efficient scavenging of heavy metals by ferric oxyhydroxides. Under the given arid to semi-arid climate the muds are additionally enriched in metals by wind-transported dust. The present study does support a relation of the actual thermal waters with neither the classical subduction-related Upper Tertiary tin, silver and gold mineralisation nor the supposed younger Sb mineralisation of Bolivia.  相似文献   

A new set of integrals of motion to propagate the perturbed two-body problem     

Giulio Baù  Claudio Bombardelli  Jesús Peláez 《Celestial Mechanics and Dynamical Astronomy》2013,116(1):53-78

A formulation of the perturbed two-body problem that relies on a new set of orbital elements is presented. The proposed method represents a generalization of the special perturbation method published by Peláez et al. (Celest Mech Dyn Astron 97(2):131–150, 2007) for the case of a perturbing force that is partially or totally derivable from a potential. We accomplish this result by employing a generalized Sundman time transformation in the framework of the projective decomposition, which is a known approach for transforming the two-body problem into a set of linear and regular differential equations of motion. Numerical tests, carried out with examples extensively used in the literature, show the remarkable improvement of the performance of the new method for different kinds of perturbations and eccentricities. In particular, one notable result is that the quadratic dependence of the position error on the time-like argument exhibited by Peláez’s method for near-circular motion under the $J_{2}$ perturbation is transformed into linear. Moreover, the method reveals to be competitive with two very popular element methods derived from the Kustaanheimo-Stiefel and Sperling-Burdet regularizations.  相似文献   

Accurate analytical approximation of asteroid deflection with constant tangential thrust     

Claudio Bombardelli  Giulio Baù 《Celestial Mechanics and Dynamical Astronomy》2012,114(3):279-295

We present analytical formulas to estimate the variation of achieved deflection for an Earth-impacting asteroid following a continuous tangential low-thrust deflection strategy. Relatively simple analytical expressions are obtained with the aid of asymptotic theory and the use of Peláez orbital elements set, an approach that is particularly suitable to the asteroid deflection problem and is not limited to small eccentricities. The accuracy of the proposed formulas is evaluated numerically showing negligible error for both early and late deflection campaigns. The results will be of aid in planning future low-thrust asteroid deflection missions.  相似文献   

The Reticulatus method for shear strengthening of fair-faced masonry   总被引：1，自引：1，他引：0  

Marco Corradi  Antonio Borri  Giulio Castori  Romina Sisti 《Bulletin of Earthquake Engineering》2016,14(12):3547-3571

This paper presents the results of several experimental campaigns recently carried out by the authors and devoted to the investigation of the mechanical performance of wall panels strengthened by applying repointing mortar and high strength stainless steel or composite cords. The reinforcement system, known as Reticulatus, allows the reinforcement of regular and irregular-shape masonry walls, when the fair-faced aspect must be kept. In the perspective of using this reinforcement method, this article summarizes the research that has been done so far, presenting new original test results and discussing the design procedures. Twenty-two square wall panels were loaded in their plane by means of a single point load acting through the panel’s diagonal. Experimental results are presented for four types of cord reinforcement using matched samples, reinforced and not. Increases in shear strength from 15 to 170 % were achieved for the strengthened panels. Each wall panel was loaded well into the lateral post-elastic regime and then unloaded. Experimental results were in good agreement with predictions from simple models which assume the wall panels to behave like a plate, neglecting the contribution of the repointing mortar, and accounting for the non-linear behavior of the masonry.  相似文献