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221.
Site response studies and seismic microzoning in the Middle Aterno valley (L��aquila, Central Italy)
G. Lanzo F. Silvestri A. Costanzo A. d��Onofrio L. Martelli A. Pagliaroli S. Sica A. Simonelli 《Bulletin of Earthquake Engineering》2011,9(5):1417-1442
Following the April 6th, 2009 Abruzzo mainshock, the Italian Civil Protection Department promoted a multidisciplinary study
aimed at developing seismic microzonation maps for post-earthquake reconstruction planning. In the framework of this project,
a Working Group, including the authors, was assembled to carry out a microzonation study on six villages located in the Middle
Aterno valley. This paper focuses on the villages of Castelnuovo and Poggio Picenze, which experienced MCS intensity values
of IX–X and VIII–IX, respectively. 1D and 2D linear equivalent site response analyses were carried out on representative geological
cross-sections through the damaged centres and the expansion zones. The subsoil models resulting from geological, geotechnical
and geophysical investigations were calibrated by comparing numerical amplification functions, in the linear range, with horizontal-to-vertical
spectral ratio derived from both aftershocks and noise recordings. The input motions adopted for the analyses were five artificial
accelerograms compatible with three response spectra obtained from the Italian seismic code, as well as from ad hoc probabilistic
and deterministic studies. The results were expressed in the form of horizontal profiles of amplification factors in terms
of peak ground acceleration, FPGA, as well as of the Housner intensity, FH, in two different range of periods; this latter parameter was shown to be almost
independent of the input motion and allowed to express the dependency of site amplification on the frequency range. The amplification
factors computed along the representative geological sections were finally extended with a rational procedure to the surrounding
areas to draw Grade-3 microzonation maps. 相似文献
222.
Antonio Puccini Gerti Xhixha Stefano Cuccuru Giacomo Oggiano Merita Kaçeli Xhixha Fabio Mantovani Carlos Rossi Alvarez Leonardo Casini 《Environmental Earth Sciences》2014,71(1):393-405
This study focuses on the radiological characterization of granitoid outcrops and dimension stones using in situ gamma-ray spectrometry. Extensive measurements were performed on 210 granitoid outcrops of the Corsica-Sardinia Batholith. The large statistical sample allowed us to improve the analysis by considering a log-normal distribution of radioelements and propagating the uncertainties using Monte Carlo method. The activity concentrations of 40K, 226Ra (238U) and 232Th in C-SB area were 1,177 ?304 +408 , 60 ?23 +36 and 69 ?25 +38 Bq/kg (at 1σ uncertainty). The median abundance of K, U and Th on the Variscan C-SB was higher than the average values of the upper continental crust and was comparable with Variscan belt. This corresponds to an outdoor absorbed dose rate of 124 ?26 +33 nGy/h at 1σ uncertainty which is 3σ higher than the population-weighted average absorbed dose rate (60 nGy/h). Seven commercial granites (Rosa Beta, Ghiandone, Giallo San Giacomo, Rosa Cinzia, Grigio Malaga, Bianco Sardo and Grigio Perla) were investigated to characterize their radiological hazard through 147 measurements taken in 73 extractive quarries. All of the commercial granites were categorized as A2 material based on their activity concentration indices, excluding (at the 3σ level) any restriction on their utilization as superficial materials. Rosa Beta, Grigio Malaga, Grigio Perla and Bianco Sardo can also be used as bulk materials as they can be included in the A1 category. In the case of Ghiandone, Giallo San Giacomo and Rosa Cinzia, we are confident of an A1 classification only at the 1σ level. 相似文献
223.
Intrinsic vulnerability assessment of Saturnia thermal aquifer by means of three parametric methods: SINTACS,GODS and COP 总被引:2,自引:1,他引:1
Enrico Guastaldi Luca Graziano Giovanni Liali Fabio Nunzio Antonio Brogna Alessio Barbagli 《Environmental Earth Sciences》2014,72(8):2861-2878
Three different parametric methods for the evaluation of intrinsic vulnerability to pollution have been applied in a hydrothermal carbonate aquifer located in central-northern Italy and the results obtained were compared with each other. The study area, large, approximately 152 km2, lies in an area of the northern Apennines. The investigated aquifer feeds the hot thermal springs of Saturnia. The vulnerability assessment methods used are: SINTACS, GODS and COP. The vulnerability maps obtained were first individually examined, and then they were compared with each other by means of spatial analysis. These maps show similar results for the estimation of the vulnerability just in some areas. SINTACS yields areas potentially vulnerable to pollution along the Albegna River and its major tributaries in the northern part of the study area. The GODS index map reflects the great importance that this method gives to the lithological characteristics of the unsaturated zone in the subdivision of areas with different vulnerability. GODS and COP methods agree in classifying low vulnerability in the most part of central-southern study area, where the aquifer is confined by the Pliocene clay deposits. Based on the conceptual model of groundwater flow developed for the aquifer under investigation, COP seems the most appropriate method among those applied in this work, in particular with regard to the assessment of the vulnerability of the recharge area of thermal groundwater. Located in the northern part of the study area, where karst carbonate formations of the Tuscan Nappe outcrop, this recharge area is classified by the COP method as highly vulnerable to pollution. 相似文献
224.
Fabio R. Marin James W. Jones Abraham Singels Frederick Royce Eduardo D. Assad Giampaolo Q. Pellegrino Flávio Justino 《Climatic change》2013,117(1-2):227-239
This study evaluated the effects of climate change on sugarcane yield, water use efficiency, and irrigation needs in southern Brazil, based on downscaled outputs of two general circulation models (PRECIS and CSIRO) and a sugarcane growth model. For three harvest cycles every year, the DSSAT/CANEGRO model was used to simulate the baseline and four future climate scenarios for stalk yield for the 2050s. The model was calibrated for the main cultivar currently grown in Brazil based on five field experiments under several soil and climate conditions. The sensitivity of simulated stalk fresh mass (SFM) to air temperature, CO2 concentration [CO2] and rainfall was also analyzed. Simulated SFM responses to [CO2], air temperature and rainfall variations were consistent with the literature. There were increases in simulated SFM and water usage efficiency (WUE) for all scenarios. On average, for the current sugarcane area in the State of São Paulo, SFM would increase 24 % and WUE 34 % for rainfed sugarcane. The WUE rise is relevant because of the current concern about water supply in southern Brazil. Considering the current technological improvement rate, projected yields for 2050 ranged from 96 to 129 t?ha?1, which are respectively 15 and 59 % higher than the current state average yield. 相似文献
225.
Ivan Martini Mauro Coltorti Paul P.A. Mazza Marco Rustioni Fabio Sandrelli 《Quaternary Research》2014
The skeleton of a young prime adult cave bear, Ursus spelaeus, was found in Chiostraccio Cave (Siena, Tuscany, central Italy), only slightly buried under rock falls. The specimen was dated yielding a conventional age of 24,030 ± 100 14C yr BP (29,200–28,550 cal yr BP), which makes it the latest known representative of the species in Italy. The skeleton was accompanied by the remains of wolf (Canis lupus), wild boar (Sus scrofa), aurochs (Bos primigenius), red deer (Cervus elaphus), roe deer (Capreolus capreolus), bat (Vespertinus murinus), and crow (Corvus monedula). The site seems confirming that the latest Italian U. spelaeus populations shared the risk of intrusion. The association of the cave bear with other animals suggests that the assemblage is an attritional palimpsest of remains of different species not originally associated in life. Cave bears were probably more vegetarian than brown bears and possibly became extinct when plant productivity dropped at the onset of MIS 2. Central and southern Italy may have offered isolated and sheltered refugia for cave bears. 相似文献
226.
Fabio lapponi Thilo Bechstädt Maria Boni David A. Banks Jens Schneider 《Sedimentology》2014,61(2):411-443
Burial hydrothermal dolomitization is a common diagenetic modification in sedimentary basins with implications for oil and gas reservoir performance. Outcrop analogues represent an easily accessible source of data to refine the genetic models and assess risk in hydrocarbon exploration and production. The Palaeozoic succession of northern Spain contains numerous excellent exposures of epigenetically dolomitized limestones, particularly in the Carboniferous and Cambrian. The epigenetic dolomites in the Cambrian carbonates of the Láncara Formation are volumetrically small, but have a large aerial distribution across different tectonic units of the Variscan fold and thrust belt. Coarse crystals, abundant saddle dolomite cement, negative δ18O and fluid inclusion homogenization temperatures between 80°C and 120°C characterize these dolomites, which are petrographically and geochemically similar to the tens of kilometre‐sized hydrothermal dolomites replacing the Upper Carboniferous succession in the same area. In both cases, the dolomitizing fluids are derived from highly evaporated sea water, modified to a limited degree through fluid‐rock interaction. The dolomitization events affecting both Cambrian and Carboniferous strata are probably related to the same post‐orogenic hydrothermal fluid flow. The formation of the post‐collisional (latest Carboniferous) Cantabrian arc fostered dolomitization: the extension related to bending of the arc generated deep‐reaching faults and strike‐slip movements, which favoured the circulation of hot dolomitizing fluids in the outer parts of this orocline. A similar dolomitization process affected other areas of Europe after the main stages of the Variscan orogeny. Dolomitization was a continuous, uninterrupted, isochemical process. Limestone replacement resulted in a major porosity redistribution and focused the fluid flow into the newly created porous zones. Replacement was followed immediately by partial to complete cementation of the pores (including zebra fabrics and vugs) with saddle dolomite. The amount of porosity left depends on the volume of cement and therefore on the volume of fluids available. 相似文献
227.
Lucio Mayer Fabio Governato Monica Colpi Ben Moore Thomas R. Quinn Carlton M. Baugh 《Astrophysics and Space Science》2001,276(2-4):375-382
We study the evolution of galaxy satellites with high resolutionN-body simulations. Satellites are modelled as replicas of typical low and high surface brightness galaxies (LSBs and HSBs).
Encounters on high eccentricity orbits (as typical in hierarchical models of galaxy formation) strip LSBs of most of their
stars and tend to decrease their surface brightness. In contrast, bar instability in HSBs leads to substantial loss of angular
momentum of the stellar component and to an increase in central surface brightness. In both cases the remnant resembles a
spheroidal galaxy with an exponential surface brightness profile. A simple modelling of colour evolution and interaction-driven
star formation gives M/L ratios for the remnants that are roughly consistent with observations. These results suggest an evolutionary scenario for
the dwarf galaxies in our Local Group, faint dSphs being the descendants of LSBs and brighter dSphs/dEs being the final state
of HSB satellites.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
228.
Darren Reed Fabio Governato Thomas Quinn Jeffrey Gardner Joachim Stadel George Lake 《Monthly notices of the Royal Astronomical Society》2005,359(4):1537-1548
We use cosmological Λ cold dark matter (CDM) numerical simulations to model the evolution of the substructure population in 16 dark matter haloes with resolutions of up to seven million particles within the virial radius. The combined substructure circular velocity distribution function (VDF) for hosts of 1011 to 1014 M⊙ at redshifts from zero to two or higher has a self-similar shape, is independent of host halo mass and redshift, and follows the relation d n /d v = (1/8)( v cmax / v cmax,host )−4 . Halo to halo variance in the VDF is a factor of roughly 2 to 4. At high redshifts, we find preliminary evidence for fewer large substructure haloes (subhaloes). Specific angular momenta are significantly lower for subhaloes nearer the host halo centre where tidal stripping is more effective. The radial distribution of subhaloes is marginally consistent with the mass profile for r ≳ 0.3 r vir , where the possibility of artificial numerical disruption of subhaloes can be most reliably excluded by our convergence study, although a subhalo distribution that is shallower than the mass profile is favoured. Subhalo masses but not circular velocities decrease towards the host centre. Subhalo velocity dispersions hint at a positive velocity bias at small radii. There is a weak bias towards more circular orbits at lower redshift, especially at small radii. We additionally model a cluster in several power-law cosmologies of P ∝ kn , and demonstrate that a steeper spectral index, n , results in significantly less substructure. 相似文献
229.
230.