Shallow structure of the Somma–Vesuvius volcano from 3D inversion of gravity data     

Federico Cella  Maurizio Fedi  Giovanni Florio  Marino Grimaldi  Antonio Rapolla 《Journal of Volcanology and Geothermal Research》2007

A gravity investigation was carried out in the Somma–Vesuvius complex area (Campania, Italy) based on a dataset recently enlarged with new measurements. These cover the volcanic top and fill some other important spatial gaps in previous surveys. Besides the new gravity map of the Vesuvius, we also present the results of a 3D inverse modelling, carried out by using constraints from deep well exploration and seismic reflection surveys. The resulting density model provides a complete reconstruction of the top of the carbonate basement. This is relevant mostly on the western side of the survey area, where no significant information was previously available. Other new information regards the Somma–Vesuvius structure. It consists of an annular volume of rocks around the volcanic vent and that extends down to the carbonate basement. It results to be denser with respect to the surrounding sedimentary cover of the Campanian Plain and to the material located just along the central axis of the volcanic structure. The coherence between these features and other geophysical evidences from previous studies, will be discussed together with the other results of this research.  相似文献   

An experimental facility for investigating hydromagmatic eruptions at high-pressure and high-temperature with application to the importance of magma porosity for magma-water interaction     

Raffaello Trigila  Maurizio Battaglia  Michael Manga 《Bulletin of Volcanology》2007,69(4):365-372

An experimental facility has been developed to investigate magma-water interaction (MWI). The facility operates in a high-pressure and high-temperature environment, with temperatures up to 1,200°C and pressures up to 200 MPa. Cylindrical sample-holders (20 by 180 mm in size) are heated conductively to yield a three phase (melt, crystals and gas) system, and then water (or other fluid) is injected into the sample through a capillary tube (diameter 0.5 mm, length ca. 1,000 mm) under controlled conditions. Pressure, volume and temperature changes are continuously recorded during every phase of the experiments. To test this facility, MWI is studied at subliquidus temperatures (800 and 900°C) and pressure (8 MPa), using a leucite tephrite sample with two different initial grain sizes. Because of the grain-size dependence of sintering, the two starting materials produce magmas with different textures at the same temperature: porous magma for large initial grain sizes and dense magma for small initial grain sizes. In these experiments 1.5 g of water at room temperature is injected into 6.0 g of partially molten sample at velocities ranging from 1 to 3 m/s. We find that the extent of fragmentation and transport caused by MWI are mainly controlled by the texture of the interacting sample with explosive interaction occurring only for porous magmas.  相似文献   

Source ambiguity from an estimation of the scaling exponent of potential field power spectra     

Tatiana Quarta  Maurizio Fedi  & Angelo De Santis 《Geophysical Journal International》2000,140(2):311-323

An analysis of the field scaling power spectrum yields useful information about the source distribution, but it is uncertain whether deterministic, random, fractal or mixed approaches have to be used for the interpretation. To this end, the scaling properties of potential field spectra are analysed for a number of different source models of geological interest. Besides the models of Naidu (purely random sources) and Spector and Grant (gross block statistical ensembles) we consider other types of density and magnetization distributions with spectral exponents in the fractal range, such as a single homogeneous body with a random white source distribution. Spectral slopes in the fractal range are obtained.
We also study the effects of important natural sources, such as salt domes and sedimentary basins, representing them with simple Gaussians or combinations of Gaussian signals. The same spectral slopes as for gravity signals generated by 3-D fractal source distributions are found for them. Hence the power law decay of the field is not a characteristic only of fractal source models.
If a 3-D fractal source distribution is assumed a priori , a way of verifying the goodness of the model is to examine the whitened field at source level. The probability that the whitened field derives from a random white population is estimated for synthetic and real anomalies by applying the usual statistical tests.  相似文献   

The Sponge Community of a Semi-Submerged Mediterranean Cave   总被引：1，自引：0，他引：1  

Giuseppe Corriero  Lidia Scalera Liaci  Daniela Ruggiero  & Maurizio Pansini 《Marine Ecology》2000,21(1):85-96

Abstract. The sponge fauna of a semi-submerged cave from the Tremiti Archipelago (Adriatic Sea) was studied, and its distribution was analyzed in relation to abiotic (water-movement and light gradients) and biotic (algae and anthozoan substrate cover) ecological factors. Fifty-five species of sponges were recorded. The number of species and the abundance values of sponges increase in the first part of the cave, then progressively decrease, with a sharp fall at the end of the cave. The quick disappearance of algae along the light gradient allows sponges to thrive in the first portion of the cave. The subsequent, progressive decrement of sponges could be the result of food depletion phenomena due to a long persistence of the water body in this long cavity. A high water-turbulence, due to the peculiar morphology of the cave and indicated by the recorded values of water-movement, occurs at the end of the cavity and probably determines the sharp decrement of sponges in the inner portion of the cave. This turbulence may also explain the absence of typical still-water cave species and probably affects the type of development (shape, overgrowth) of the sponges in the community.  相似文献   

The role of petrography on the thermal decomposition and burnability of limestones used in industrial cement clinker     

Nicoletta Marinoni  Andrea Bernasconi  Giovanna Della Porta  Maurizio Marchi  Alessandro Pavese 《Mineralogy and Petrology》2015,109(6):719-731

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Stability of the sponge assemblage of Mediterranean coralligenous concretions along a millennial time span     

Marco Bertolino  Barbara Calcinai  Riccardo Cattaneo‐Vietti  Carlo Cerrano  Anna Lafratta  Maurizio Pansini  Daniela Pica  Giorgio Bavestrello 《Marine Ecology》2014,35(2):149-158

The Mediterranean coralligenous substratum is a hard bottom of biogenic origin, mainly composed of calcareous algae, growing in dim light conditions. Sponges are among of the most representative taxa of the coralligenous assemblages, with more than 300 recorded species of different habits: massive, erect, boring and insinuating. When sponges die, their siliceous spicules remain trapped in the biogenic concretion, offering the opportunity to describe the coralligenous spongofauna over a very long span of time, virtually dating back to a large part of the Holocene period. The data reported here were obtained from core samples collected from four coralligenous concretions. Each block was collected in a different locality of the Ligurian Sea: Santo Stefano Shoals, Bogliasco, Punta del Faro (Portofino Promontory) and Punta Manara. Radiocarbon age determinations indicate for these conglomerates a maximal age between 1600 and 3100 years. The spicules trapped in the cores show deep dissolution marks in the form of circular holes on their surface or present an enlargement of the axial canal. However, their original shape, generally intact, suggests the absence of mechanical injuries and allows a tentative identification at the species level. The analysis of these old spicules reveals an ancient sponge assemblage composed of 30 recognisable species. This indicates that almost one half of the sponge community today settled on coralligenous substrata has been present in the conglomerates for their entire existence.  相似文献   

Reply to comment on ��A stratigraphic and geophysical approach to studying the deep-circulating groundwater and thermal springs, and their recharge areas, in Cimini Mountains�CViterbo area, central Italy��: paper published in Hydrogeology Journal (2010) 18:1319�C1341, by Ugo Chiocchini, Fabio Castaldi, Maurizio Barbieri, Valeria Eulilli     

Ugo Chiocchini  Fabio Castaldi  Maurizio Barbieri  Valeria Eulilli 《Hydrogeology Journal》2011,19(4):949-952

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The impact of aging on the rotation rate of calcium plages in the years 1967–1977     

Maurizio Ternullo 《Solar physics》1987,112(1):153-163

An analysis of Ca ii spectroheliograms obtained at Catania Astrophysical Observatory throughout the years 1967–1977 has been carried out, to throw light on the complex relationship linking (Ternullo, 1986) the angular rotation rate of Ca plages with their age, as well as with solar cycle phase, and with latitude. Given the rotation law w =, a + b sin² I, solar-cycle-related oscillatory properties both of a and b coefficients are described, both for young and old Ca plages.The aging-dependent rate-increments vary, for each epoch, both in module and sign with latitude; that results in deep distortions of the differential rotation latitudinal profile, which exhibits, when old plages are taken into account, a fine structure (Ternullo, 1987). Such a fine structure is absent in the young plage differential rotation profile.Throughout the time interval under examination, the torsional waves observed by Howard and LaBonte (1980) have appeared to be in close spatial relationship with the latitude bands where aging-dependent rate increments occur.

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Quantum theory of line formation in a magnetic field     

Egidio Landi Degl'innocenti  Maurizio Landi Degl'innocenti 《Solar physics》1972,27(2):319-329

The transfer equations for the Stokes parameters in the presence of magnetic field and under the hypothesis of LTE are derived in an original way by the use of density matrix techniques.The results are substantially the same as those previously obtained by other authors. We finally compare our results to the previous ones in order to clarify some discrepancies still present in the literature.  相似文献   

Forward and inverse modeling of magnetic data under complex magnetism effects:Remanence, self-demagnetization and magnetic anisotropy     

Shuang Liu  Xiangyun Hu  Maurizio Fedi  Rixiang Zhu 《《地质学报》英文版》2018,92(Z1):325-325

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