Three-dimensional V_P and V_P /V_S models of the upper crust in the Friuli area (northeastern Italy)     

G. F. Gentile  G. Bressan  L. Burlini  & R. De Franco 《Geophysical Journal International》2000,141(2):457-478

3-D images of P velocity and P - to S -velocity ratio have been produced for the upper crust of the Friuli area (northeastern Italy) using local earthquake tomography. The data consist of 2565 P and 930 S arrival times of high quality. The best-fitting V _P and V _P / V _S 1-D models were computed before the 3-D inversion. V _P was measured on two rock samples representative of the investigated upper layers of the Friuli crust. The tomographic V _P model was used for modelling the gravity anomalies, by converting the velocity values into densities along three vertical cross-sections. The computed gravity anomalies were optimized with respect to the observed gravity anomalies. The crust investigated is characterized by sharp lateral and deep V _P and V _P / V _S anomalies that are associated with the complex geological structure. High V _P / V _S values are associated with highly fractured zones related to the main faulting pattern. The relocated seismicity is generally associated with sharp variations in the V _P / V _S anomalies. The V _P images show a high-velocity body below 6 km depth in the central part of the Friuli area, marked also by strong V _P / V _S heterogeneities, and this is interpreted as a tectonic wedge. Comparison with the distribution of earthquakes supports the hypothesis that the tectonic wedge controls most of the seismicity and can be considered to be the main seismogenic zone in the Friuli area.  相似文献   

Analysis of suspended sediment dynamics at event scale: comparison between a Mediterranean and an Alpine basin     

Stefano Giorgio Pagano  Adriana García-Rama  Francesco Gentile  Mario Aristide Lenzi 《水文科学杂志》2019,64(8):948-961

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Nonlinear analysis of masonry structures using fiber-section line elements     

Matteo Peruch  Enrico Spacone  Guido Camata 《地震工程与结构动力学》2019,48(12):1345-1364

For seismic analysis of unreinforced masonry (URM) buildings characterized by a box-like behavior, a widely accepted model is based on the equivalent frame idealization of walls. The equivalent frame model uses 1D elements to represent the vertical piers and horizontal spandrels which are connected by rigid nodes. The mechanical characterization of the elements is one of the crucial aspects to predict reasonably the building seismic behavior. Through the comparison with pseudo-static and dynamic experimental tests performed on two-story full-scale buildings, this paper validates the frame modeling in the OpenSees framework, which includes a fiber-section force-based beam element for the axial-flexural behavior, coupled with a cyclic shear-deformation phenomenological law.  相似文献   

The stresses and dynamics of smallholder coffee systems in Jamaica’s Blue Mountains: a case for the potential role of climate services     

Zack Guido  Tim Finan  Kevon Rhiney  Malgosia Madajewicz  Valerie Rountree  Elizabeth Johnson  Gusland McCook 《Climatic change》2018,147(1-2):253-266

Access to climate information has the potential to build adaptive capacity, improve agricultural profitability, and help manage risks. To achieve these benefits, knowledge of the local context is needed to inform information development, delivery, and use. We examine coffee farming in the Jamaican Blue Mountains (BM) to understand farmer livelihoods, opportunities for climate knowledge to benefit coffee production, and the factors that impinge on farmers’ ability to use climate information. Our analysis draws on interviews and 12 focus groups involving 143 participants who largely cultivate small plots. BM farmers currently experience stresses related to climate, coffee leaf rust, and production costs that interrelate concurrently and with time lags. Under conditions that reduce income, BM farmers compensate by adjusting their use of inputs, which can increase their susceptibility to future climate and disease stresses. However, farmers can also decrease impacts of future stressors by more efficiently and effectively allocating their limited resources. In this sense, managing climate, like the other stresses, is an ongoing process. While we identify climate products that can help farmers manage climate risk, the local context presents barriers that argue for interactive climate services that go beyond conventional approaches of information production and delivery. We discuss how dialogs between farmers, extension personnel, and climate scientists can create a foundation from which use can emerge.  相似文献   

The ecological implications of a Yakutian mammoth's last meal   总被引：1，自引：0，他引：1  

Bas van Geel  Andr Aptroot  Claudia Baittinger  Hilary H. Birks  Ian D. Bull  Hugh B. Cross  Richard P. Evershed  Barbara Gravendeel  Erwin J.O. Kompanje  Peter Kuperus  Dick Mol  Klaas G.J. Nierop  Jan Peter Pals  Alexei N. Tikhonov  Guido van Reenen  Peter H. van Tienderen 《Quaternary Research》2008,69(3):361-376

Part of a large male woolly mammoth (Mammuthus primigenius) was preserved in permafrost in northern Yakutia. It was radiocarbon dated to ca. 18,500 ¹⁴C yr BP (ca. 22,500 cal yr BP). Dung from the lower intestine was subjected to a multiproxy array of microscopic, chemical, and molecular techniques to reconstruct the diet, the season of death, and the paleoenvironment. Pollen and plant macro-remains showed that grasses and sedges were the main food, with considerable amounts of dwarf willow twigs and a variety of herbs and mosses. Analyses of 110-bp fragments of the plastid rbcL gene amplified from DNA and of organic compounds supplemented the microscopic identifications. Fruit-bodies of dung-inhabiting Ascomycete fungi which develop after at least one week of exposure to air were found inside the intestine. Therefore the mammoth had eaten dung. It was probably mammoth dung as no bile acids were detected among the fecal biomarkers analysed. The plant assemblage and the presence of the first spring vessels of terminal tree-rings of dwarf willows indicated that the animal died in early spring. The mammoth lived in extensive cold treeless grassland vegetation interspersed with wetter, more productive meadows. The study demonstrated the paleoecological potential of several biochemical analytical techniques.  相似文献   

The Marianas-San Marcos vein system: characteristics of a shallow low sulfidation epithermal Au–Ag deposit in the Cerro Negro district,Deseado Massif,Patagonia, Argentina     

Conrado Permuy Vidal  Diego M. Guido  Sebastián M. Jovic  Robert J. Bodnar  Daniel Moncada  Joan Carles Melgarejo  Willis Hames 《Mineralium Deposita》2016,51(6):725-748

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Permeability distribution in the Lahendong geothermal field: A blind fault captured by thermal–hydraulic simulation     

Maren Brehme  Guido Blöcher  Mauro Cacace  Yustin Kamah  Martin Sauter  Günter Zimmermann 《Environmental Earth Sciences》2016,75(14):1088

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Zur Geomorphogenie Anatoliens     

Dr. Guido Hoffmann 《International Journal of Earth Sciences》1925,16(1):17-34

Ohne Zusammenfassung  相似文献   

Subsidence due to crack closure and depressurization of hydrothermal systems: a case study from Mt Epomeo (Ischia Island,Italy)     

Vincenzo Sepe  Simone Atzori  Guido Ventura 《地学学报》2007,19(2):127-132

Levelling surveys carried out between 1990 and 2003 on the Mt Epomeo resurgent block (Ischia Island) record negative dislocations on its northern and southern flanks with a maximum subsidence rate of 1.27 cm yr⁻¹. This deformation is not associated with the cooling, crystallization or lateral drainage of magma and cannot be explained by a pressure point or prolate ellipsoid source. Results from dislocation models and the available structural and geochemical information indicate that the subsidence is due to crack closure processes along two main ENE–WSW and E–W preexisting faults, which represent the preferred pathway of CO₂ degassing from the hydrothermal system located beneath Mt Epomeo. The monitoring of the dislocations and CO₂ flux along these faults could give useful information on the dynamics of the hydrothermal system.  相似文献   

Monitoring, prediction, and early warning using ground-based radar interferometry   总被引：11，自引：8，他引：3  

Nicola Casagli  Filippo Catani  Chiara Del Ventisette  Guido Luzi 《Landslides》2010,7(3):291-301

In order to define adequate prevention measures and to manage landslide emergencies, real-time monitoring is required. This paper presents two different applications of the remote sensing technique: the ground-based synthetic aperture radar interferometry, here proposed as a monitoring and early warning support for slope instability. Data acquisitions carried out through a ground-based synthetic aperture radar interferometer, operating in K_u band, installed in front of the observed slopes, are discussed. Two case studies, based on the use of the same apparatus (formerly developed by the Joint Research Center of the European Commission and by Ellegi-LiSALab srl), are reported: the first one concerns the monitoring of a large landslide, named Ruinon (Valfurva, Italy). The second one deals with the monitoring of the NW unstable slope in the Stromboli island aimed to implementing an early warning system. Acquired interferometric data are processed to provide displacements and velocity maps of the monitored area. The monitoring services ongoing on the Ruinon landslide and on Stromboli demonstrate the capability of this technique to operate in different operative settings (i.e., different phenomena and geological framework) and for different aims (monitoring for prevention, early warning, and emergency assessment). This methodology has also been proved by national and regional authorities of civil protection in order to provide a real-time monitoring for emergency management.  相似文献