The ground-based InSAR monitoring system at Stromboli volcano: linking changes in displacement rate and intensity of persistent volcanic activity   总被引：1，自引：1，他引：0  

Federico Di Traglia  Emanuele Intrieri  Teresa Nolesini  Federica Bardi  Chiara Del Ventisette  Federica Ferrigno  Sara Frangioni  William Frodella  Giovanni Gigli  Alessia Lotti  Carlo Tacconi Stefanelli  Luca Tanteri  Davide Leva  Nicola Casagli 《Bulletin of Volcanology》2014,76(2):1-18

Stromboli volcano (Aeolian Archipelago, Southern Italy) experienced an increase in its volcanic activity from late December 2012 to March 2013, when it produced several lava overflows, major Strombolian explosions, crater-wall collapses pyroclastic density currents and intense spatter activity. An analysis of the displacement of the NE portion of the summit crater terrace and the unstable NW flank of the volcano (Sciara del Fuoco depression) has been performed with a ground-based interferometric synthetic aperture radar (GBInSAR) by dividing the monitored part of the volcano into five sectors, three in the summit vents region and two in the Sciara del Fuoco. Changes in the displacement rate were observed in sectors 2 and 3. Field and thermal surveys revealed the presence of an alignment of fumaroles confirming the existence of an area of structural discontinuity between sectors 2 and 3. High displacement rates in sector 2 are interpreted to indicate the increase in the magmastatic pressure within the shallow plumbing systems, related to the rise of the magma level within the conduits, while increased displacement rates in sector 3 are connected to the lateral expansion of the shallow plumbing system. The increases and decreases in the displacement rate registered by the GBInSAR system in the upper part of the volcano have been used as a proxy for changes in the pressure conditions in the shallow plumbing system of Stromboli volcano and hence to forecast the occurrence of phases of higher-intensity volcanic activity.  相似文献   

Landslide distribution and size in response to Quaternary fault activity: the Peloritani Range,NE Sicily,Italy          下载免费PDF全文

Francesco Bucci  Michele Santangelo  Mauro Cardinali  Federica Fiorucci  Fausto Guzzetti 《地球表面变化过程与地形》2016,41(5):711-720

Landslides contribute to dismantle active mountain ranges and faults control the location of landslides. Yet, evidence of the long‐term, regional dependency of landslides on active faults is limited. Previous studies focused on the transient effects of earthquakes on slope stability in compressive and transcurrent regimes. Here we show that in the Peloritani range, NE Sicily, Italy, one of the fastest uplifting areas in the Mediterranean, a clear geographical association exists between large bedrock landslides and active normal faults of the Messina Straits graben. By interpreting aerial photographs, we mapped 1590 landslides and sackungs and 626 fault elements and their facets in a 300 km² area in the eastern part of the range. We used the new landslide and fault information, in combination with prior geological and seismic information, to investigate the association between bedrock landslides and faults. We find that the distribution and abundance of landslides is related to the presence of large active normal faults, and matches the pattern of the local historical seismicity. Landslide material is more abundant along the East Peloritani Fault System where the long‐term activity of the faults, measured by the average yearly geological moment rate, is larger than in the West Peloritani Fault System where landslides are less abundant. Along the fault systems landslide material concentrates where the cumulated fault throws are largest. We conclude that large landslides and their cumulated volume are sensitive to local rates of tectonic deformation, and discriminate the deformation of the single fault segments that dissect the Peloritani range. Our findings are a direct test of landscape evolution models that predict higher rates of landslide activity near active faults. Our work opens up the possibility of exploiting accurate landslide and fault maps, in combination with geological and seismic information, to characterize the long‐term seismic history of poorly instrumented active regions. © 2015 The Authors Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd  相似文献   

Anatomy of the Holocene succession of the southern Venice lagoon revealed by very high-resolution seismic data     

Massimo Zecchin  Giuliano Brancolini  Luigi Tosi  Federica Rizzetto  Mauro Caffau  Luca Baradello 《Continental Shelf Research》2009

The southern portion of the Venice lagoon contains a relatively thick (up to 20 m) Holocene sedimentary body that represents a detailed record of the formation and evolution of the lagoon. New very high-resolution (VHR) seismic profiles provided a detailed investigation on depositional geometries, internal bounding surfaces and stratal relationships. These informations, combined with core analysis, allowed the identification of large- to medium-scale sedimentary structures (e.g. dunes, point bars), the corresponding sedimentary environment, and of retrogradational and progradational trends. In addition, the availability of dense seismic network produced a 3D reconstruction of the southern lagoon and the recognition of the along-strike and dip variability of the stratal architecture.  相似文献   

ANN forecast of hourly averaged AE index based on L1 IMF and plasma measurements     

Ermanno Amata  Giuseppe Consolini  Giuseppe Pallocchia  Maria Federica Marcucci 《Acta Geophysica》2009,57(1):185-196

The AE index has two components: one driven by the solar wind and one related to the magnetotail unloading process. We recall some past findings on this issue and present a new ANN algorithm for the AE forecasting at 5 and 60 min time scales, built by adding to a previous algorithm a further layer with a hyperbolic tangent transfer function and two more inputs, the output at time t and the difference between the input at time t and the output at time t - 1. We show that, at the 60 min time scale and for AE > 400 nT, the new algorithm performs better than the former one, while no improvement is obtained at the 5 min time scale. This result confirms that the AE component driven by the solar wind can be forecast, at least partially, while the unloading component may not be reproduced from solar wind inputs.  相似文献   

Density distribution functions and correlations of earthquake parameters     

Federica Magnoni  Michele Caputo   《Tectonophysics》2009,474(3-4):633-642

The statistical analysis of the source parameters of 9 earthquake sets of different types (aftershocks, scattered events, swarms) and of different seismic regions shows that the density distribution function (ddf) of the linear dimension l of a fault is represented by a negative power law, as well as the ddf of the static stress drop σ and of the scalar seismic moment M_o. It is then suggested, and tentatively verified, that also the ddf of the root mean square ground acceleration, defined as a function of l and σ, may be represented by a negative power law and that, at least in the cases examined, it scales like the ddf of σ. It is seen that the variability of the static stress drop is significant from one region to another, as is well known, but it seems remarkable also in the same seismic region (in particular in California, σ varies by several orders of magnitude) and in the different sets of events of a given region (as observed again for California). It is hypothesized that a correlation, although weak, between the stress drop and the linear dimension of a fault exists and the analyses seem not to contradict that σ may be a decreasing function of l. Finally, it is suggested that the seismicity of a region may be represented two-dimensionally as a function of the ddf of the stress drop and of the linear dimension of a fault instead of the classic b and b_o values.  相似文献   

Polycyclic aromatic hydrocarbons (PAHs) in transplanted Manila clams (Tapes philippinarum) from the Lagoon of Venice as assessed by PAHs/shell weight index: a preliminary study     

Boscolo R  Cacciatore F  Giovanardi O 《Marine pollution bulletin》2007,55(10-12):485-493

Variation of polycyclic aromatic hydrocarbons (PAHs) levels was assessed in Tapes philippinarum from the Lagoon of Venice. Clams were transplanted from a polluted area next to Porto Marghera to two rearing areas of the Southern Lagoon. Analyses of PAHs were made in sediments and clams by GC/MS at first sampling and after 30, 60 and 180 days. Principal component analysis was performed to elucidate bioaccumulation and depuration pattern and input sources. Biota-Sediment-Accumulation-Factor (BSAF) was applied to evaluate the PAHs input sources from sediment. Condition index was calculated to compare the seasonal variation of clam tissue to PAHs levels. To propose results not affected by seasonal changes in flesh weight of clams, the approach based on the calculation of PAHs/SW index was applied. From the results, it was concluded that PAHs/SW index is more recommendable to asses temporal variation of PAHs levels in Manila clams.  相似文献   

Seasonal variability of soil phosphate stable oxygen isotopes in rainfall manipulation experiments   总被引：2，自引：0，他引：2  

Alon Angert  Tal Weiner  Federica Tamburini  Stefano M. Bernasconi 《Geochimica et cosmochimica acta》2011,75(15):4216-4227

Phosphorus (P) availability limits productivity in many ecosystems worldwide. As a result, improved understanding of P cycling through soil and plants is much desirable. The use of the oxygen isotopes associated to phosphate can be used to study the cycle of P in terrestrial systems. However, changes with time in the oxygen isotopes associated to available P have not yet been evaluated under field conditions. Here we present the variations in available-P oxygen isotopes, based on resin extractions, in a semi-arid site that included plots in which the amount of rainfall reaching the soil was modified. In addition, the oxygen isotopes in the less dynamic fraction which is extractable by HCl, were also measured. The δ¹⁸O of the HCl-extractable phosphate shows no seasonal pattern and corresponds to the average value of the available phosphate of 16.5‰. This value is in the expected range for equilibration with soil water at the prevailing temperatures in the site. The δ¹⁸O values of resin-extractable P showed a range of 14.5-19.1‰ (SMOW), and evidence of seasonal variability, as well as variability induced by rainfall manipulation experiments. We present a framework for analyzing the isotopic ratios in soil phosphate and explain the variability as mainly driven by phosphate equilibration with soil water, and by the isotopic effects associated with extracellular mineralization. Additional isotopic effects result from fractionation in uptake, and the input to the soil of phosphate equilibrated in leaves. These results suggest that the δ¹⁸O of resin-extractable P is an interesting marker for the rate of biological P transformations in soil systems.  相似文献   

Platinum group minerals (PGM) in the Falcondo Ni-laterite deposit,Loma Caribe peridotite (Dominican Republic)     

Thomas Aiglsperger  Joaquin A. Proenza  Federica Zaccarini  John F. Lewis  Giorgio Garuti  Manuel Labrador  Francisco Longo 《Mineralium Deposita》2015,50(1):105-123

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A method for the assessment of the influence of bedding on landslide abundance and types     

Michele Santangelo  Ivan Marchesini  Mauro Cardinali  Federica Fiorucci  Mauro Rossi  Francesco Bucci  Fausto Guzzetti 《Landslides》2015,12(2):295-309

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Palaeoenvironmental significance of the mammalian faunas of Italy since the Pliocene     

Sophie Montuire  Federica Marcolini 《第四纪科学杂志》2002,17(1):87-96

The evolution of mammalian communities is a significant tool for reconstructing past environments and climate. In this paper, a palaeoecological and palaeoenvironmental reconstruction based on the study of the Italian mammal faunas ranging from Middle Pliocene to the Holocene is presented using the cenogram method and quantification of temperatures based on arvicolid species richness. These analyses reveal open and arid conditions during glacial periods and less open and more humid conditions during interglacials, with some differences between north and central–south Italy. Northern and Southern communities reflect similar trends in the evolution of palaeoenvironments and in the variation of the temperatures, but differences in estimated temperatures, which indicate a more temperate climate for southern Italy throughout the period, are considered here. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献