Remote sensing of Mercury's magnetospheric plasma environment via energetic neutral atoms imaging     

Stefano Orsini  Anna Milillo  Elisabetta De Angelis  Andrea Maria Di Lellis  Vincenzo Zanza  Stefano Livi 《Planetary and Space Science》2001,49(14-15)

The potentiality of exploring the plasma dynamical behavior of Mercury via energetic neutral atom (ENA) analysis is briefly discussed. The analysis of the Hermean ENA would give clues to the global magnetospheric configuration, clarifying crucial issues like the existence of radiation belts. In order to demonstrate the feasibility of ENA imaging in the Hermean environment, an empirical model of the equatorial proton distributions, originally developed for the Earth's magnetosphere, is here modified in order to be applicable to the expected conditions, according to the present knowledge of the planet. Simulations of the ENA radiation are then presented and discussed. It is shown that the simulated radiation is significantly high, especially when pointing the field of view towards the Hermean surface. The way of determining the proton flux distributions and the cross-tail electric field characteristics by using the ENA signal is discussed. Finally, a preliminary design of an ENA detector suitable for the ESA mission to Mercury ‘BepiColombo’ is proposed and discussed.  相似文献   

Carbonate slope re-sedimentation in a tectonically-active setting (Western Sicily Cretaceous Escarpment,Italy)     

Vincenzo Randazzo  Johan Le Goff  Pietro Di Stefano  John Reijmer  Simona Todaro  Maria Simona Cacciatore 《Sedimentology》2020,67(5):2360-2391

Tectonic processes are widely considered as a mechanism causing carbonate platform margin instabilities leading to the emplacement of mass transport deposits and calciturbidites. However, only few examples establishing a clear link between tectonics and re-sedimentation processes are known from the literature. The two-dimensional and three-dimensional wire-cut walls of hundreds of quarries extracting ornamental limestones (for example, Perlato di Sicilia) from the Western Sicily Cretaceous Escarpment in Italy expose a series of mass transport deposits. The depositional architecture, spatial facies distribution and sedimentary features of these deposits were studied in detail. Thin section analysis was used to define the microfacies characteristics and to determine the age of the re-sedimented limestones. Eleven facies types grouped into four facies associations were recognized that defined specific depositional processes and environments. The stratigraphic architecture of the slope was reconstructed using four composite facies successions based on the detailed analysis and correlation of the field sections. The palaeoslope orientation was reconstructed based on the analysis of synsedimentary faults, slump scars and pinch-out geometries. The Western Sicily Cretaceous Escarpment was strongly influenced by synsedimentary transtensional tectonics in combination with magmatic processes, as suggested by the presence of tuffites and pillow lava intercalations within the re-sedimented carbonate series. These volcanics point to a major role of crustal shear as a trigger for mass transport deposit emplacement. The facies distribution along the Western Sicily Cretaceous Escarpment delivers new insights into the deformation processes accompanying the crustal extension of the Cretaceous western Tethys realm.  相似文献   

Fluvial dynamics and 14C-10Be disequilibrium on the Bolivian Altiplano     

Kristina Hippe  Tiemen Gordijn  Vincenzo Picotti  Irka Hajdas  John D. Jansen  Marcus Christl  Christof Vockenhuber  Colin Maden  Naki Akçar  Susan Ivy-Ochs 《地球表面变化过程与地形》2019,44(3):766-780

Determining sediment transfer times is key to understanding source-to-sink dynamics and the transmission of environmental signals through the fluvial system. Previous work on the Bolivian Altiplano applied the in situ cosmogenic ¹⁴C-¹⁰Be-chronometer to river sands and proposed sediment storage times of ~10–20 kyr in four catchments southeast of Lake Titicaca. However, the fidelity of those results hinges upon isotopic steady-state within sediment supplied from the source area. With the aim of independently quantifying sediment storage times and testing the ¹⁴C-¹⁰Be steady-state assumption, we dated sediment storage units within one of the previously investigated catchments using radiocarbon dating, cosmogenic ¹⁰Be-²⁶Al isochron burial dating, and ¹⁰Be-²⁶Al depth-profile dating. Palaeosurfaces appear to preserve remnants of a former fluvial system, which has undergone drainage reversal, reduction in catchment area, and local isostatic uplift since ~2.8 Ma. From alluvium mantling the palaeosurfaces we gained a deposition age of ~580 ka, while lower down fluvial terraces yielded ≤34 ka, and floodplains ~3–1 ka. Owing to restricted channel connectivity with the terraces and palaeosurfaces, the main source of channel sediment is via reworking of the late Holocene floodplain. Yet modelling a set of feasible scenarios reveals that floodplain storage and burial depth are incompatible with the ¹⁴C-¹⁰Be disequilibrium measured in the channel. Instead we propose that the ¹⁴C-¹⁰Be offset results from: (i) non-uniform erosion whereby deep gullies supply hillslope-derived debris; and/or (ii) holocene landscape transience associated with climate or human impact. The reliability of the ¹⁴C-¹⁰Be chronometer vitally depends upon careful evaluation of sources of isotopic disequilibrium in a wide range of depositional and erosional landforms in the landscape. © 2018 John Wiley & Sons, Ltd.  相似文献   

Analysis of one-dimensional models for exchange flows under strong stratification     

Kaptein  Steven J.  van de Wal  Koen J.  Kamp  Leon P. J.  Armenio  Vincenzo  Clercx  Herman J. H.  Duran-Matute  Matias 《Ocean Dynamics》2020,70(1):41-56

Ocean Dynamics - One-dimensional models of exchange flows driven by horizontal density gradients are well known for performing poorly in situations with weak turbulent mixing. The main issue with...  相似文献   

Jurassic stratigraphy of the Belluno Basin and Friuli Platform: a perspective on far-field compression in the Adria passive margin     

Vincenzo Picotti  Miriam Cobianchi 《Swiss Journal of Geoscience》2017,110(3):833-850

Anomalous patterns of the sedimentary architecture have been recognized in passive margins, and only recently they have been associated with plate reorganization or compressional deformations propagating from distant margins. With the aim of discussing the sedimentary architecture and the potential tectonic perturbations to the passive margin pattern, we present the revision of the stratigraphy of a fossil passive margin, involved in the retrobelt of the Alpine orogeny. The main events at the transition from rifted to passive margin have been controlled by palaeoceanography, i.e. the trophic state of surface waters that hampered the carbonate photozoan productivity for a long period between Toarcian and Callovian. Toward the latest Bajocian–earliest Bathonian, the platform productivity increased, dominated by ooids. A regressional trend up to the Middle Bathonian allowed the rapid infilling of the previous rift basin. The successive aggradation in the platform was still dominated by non-skeletal grains until the Early Oxfordian. The Middle Oxfordian to Early Kimmeridgian was a time of recovery of the palaeoceanographic conditions allowing the establishment of a hydrozoan/coral rich platform. The sedimentation rates in the platform increased at the margin of the productive Friuli–Adriatic Platform. From Late Kimmeridgian on, the sedimentation rates at the platform margin returned to the pre-Oxfordian values. At the scale of the whole Adriatic Platform, the Middle Oxfordian to Early Kimmeridgian interval is variable in thickness from 0 to 800 m, and it depicts a couple of folds of around 80–100 km of wavelength. The subsidence analysis of wells and composite logs from literature suggests this interval as a perturbation to the passive margin trend of around 3 Myr of duration. We interpret this folding event, superimposed to the passive margin subsidence, as the far field expression of the transition from intraoceanic to continental obduction, occurred at the eastern Adria active margin.  相似文献   

U?Pb and 40Ar?39Ar geochronology of Palaeozoic units in the northern Apennines: determining protolith age and alpine evolution using the Calamita Schist and Ortano Porphyroid     

Giovanni Musumeci  Francesco Mazzarini  Massimo Tiepolo  Gianfranco Di Vincenzo 《Geological Journal》2011,46(4):288-310

In the northern Apennines, the Palaeozoic basement involved in the Late Oligocene–Middle Miocene nappe stack contains metamorphic units for which hypothetical ages have been assigned on the basis of lithological correlations with the Palaeozoic formations of the Variscan chain in Sardinia. This uncertainty concerning the age poses limitations to reconstructing the Palaeozoic stratigraphy, defining the Alpine and pre‐Alpine histories and correlations with other domains of the Variscan chain. We present the U Pb age of detrital zircon and the ⁴⁰Ar ³⁹Ar age of metamorphic muscovite for the Calamita Schist and Ortano Porphyroid, two metamorphic units of undetermined Palaeozoic age cropping out in the eastern Elba Island. The radioisotopic data allows us to: (i) define the Early Carboniferous and Middle Ordovician ages for the Calamita Schist and Ortano Porphyroid, respectively, as well as their derivation (flysch deposit and magmatic rocks); (ii) pose some constraints concerning their alpine tectonic and metamorphic histories. These new data generate a more precise reconstruction of the Palaeozoic sequence in the northern Apennines, and they document that the Palaeozoic basement involved in the alpine deformation underwent internal stacking with an inversion of the original sequence. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Discussion 1 on "Introspection on improper seismic retrofit of Basilica Santa Maria di Collemaggio after 2009 Italian earthquake" by G.P.Cimellaro,A.M.Reinhorn and A.De Stefano     

Vincenzo Ciampi 《地震工程与工程振动(英文版)》2012,11(2):281-282

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New seismo-stratigraphic and marine magnetic data of the Gulf of Pozzuoli (Naples Bay, Tyrrhenian Sea, Italy): inferences for the tectonic and magmatic events of the Phlegrean Fields volcanic complex (Campania)     

Gemma Aiello  Ennio Marsella  Vincenzo Di Fiore 《Marine Geophysical Researches》2012,33(2):97-125

A detailed reconstruction of the stratigraphic and tectonic setting of the Gulf of Pozzuoli (Naples Bay) is provided on the basis of newly acquired single channel seismic profiles coupled with already recorded marine magnetics gathering the volcanic nature of some seismic units. Inferences for the tectonic and magmatic setting of the Phlegrean Fields volcanic complex, a volcanic district surrounding the western part of the Gulf of Naples, where volcanism has been active since at least 50 ka, are also discussed. The Gulf of Pozzuoli represents the submerged border of the Phlegrean caldera, resulting from the volcano-tectonic collapse induced from the pyroclastic flow deposits of the Campanian Ignimbrite (35 ka). Several morpho-depositional units have been identified, i.e., the inner continental shelf, the central basin, the submerged volcanic banks and the outer continental shelf. The stratigraphic relationships between the Quaternary volcanic units related to the offshore caldera border and the overlying deposits of the Late Quaternary depositional sequence in the Gulf of Pozzuoli have been highlighted. Fourteen main seismic units, both volcanic and sedimentary, tectonically controlled due to contemporaneous folding and normal faulting have been revealed by geological interpretation. Volcanic dykes, characterized by acoustically transparent sub-vertical bodies, locally bounded by normal faults, testify to the magma uprising in correspondence with extensional structures. A large field of tuff cones interlayered with marine deposits off the island of Nisida, on the western rim of the gulf, is related to the emplacement of the Neapolitan Yellow Tuff deposits. A thick volcanic unit, exposed over a large area off the Capo Miseno volcanic edifice is connected with the Bacoli-Isola Pennata-Capo Miseno yellow tuffs, cropping out in the northern Phlegrean Fields.  相似文献   

Seismic displacement-based design of embedded retaining structures     

Manuela Cecconi  Vincenzo Pane  Alessia Vecchietti 《Bulletin of Earthquake Engineering》2015,13(7):1979-2001

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On the criteria to create a susceptibility map to debris flow at a regional scale using Flow-R   总被引：1，自引：1，他引：0  

Roberta Pastorello  Tamara Michelini  Vincenzo D’Agostino 《山地科学学报》2017,14(4):621-635

Studies on susceptibility to debris flows at regional scale(100-1000 km~2) are important for the protection and management of mountain areas. To reach this objective, routing models, mainly based on land topography, can be used to predict susceptible areas rapidly while necessitating few input data. In this research, Flow-R model is implemented to create the susceptibility map for the debris flow of the Vizze Valley(BZ, North-Eastern Italy; 134 km~2). The analysis considers the model application at local scale for three sub-catchments and then it explores the model upscaling at the regional scale by verifying two methods to generate the source areas of debris-flow initiation. Using data of an extreme event occurred in the Vizze Valley(4 August 2012) and historical information, the modeling verification highlights that the propagation parameters are relatively simple to set in order to obtain correct runout distances. A double DTM filtering-using a threshold for the upslope contributing area(0.1 km~2) and a threshold for the terrain-slope angle(15°)-provides a satisfactory prediction of source areas and susceptibility map within the geological conditions of the Vizze Valley.  相似文献