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1.
Fabio Trincardi Alessandro Amorosi Alessandro Bosman Annamaria Correggiari Fantina Madricardo Claudio Pellegrini 《Basin Research》2020,32(2):402-418
Reconstructions of ancient delta systems rely typically on a two-dimensional (2D) view of prograding clinothems but may miss their three-dimensional (3D) stratigraphic complexity which can, instead, be best documented on modern delta systems by integrating high-resolution geophysical data, historical cartography, core data and geomorphological reconstructions offshore. We quantitatively compare three precisely positioned, high-resolution multi-beam bathymetry maps in the delta front and pro delta sectors (0.3 to 10 m water depth) of Po di Pila, the most active of the modern Po Delta five branches. By investigating the detailed morphology of the prograding modern Po Delta, we shed new light on the mechanisms that control the topset to foreset transition in clinothems and show the temporal and spatial complexity of a delta and its pro delta slope, under the impact of oceanographic processes. This study documents the ephemeral nature of the rollover point at the transition between sandy topset (fluvial, delta plain to mouth-bar) and muddy seaward-dipping foreset deposits advancing, in this case, in >20 m of water depth. Three multibeam surveys, acquired between 2013 and 2016, document the complexity in space and time of the topset and foreset regions and their related morphology, a diagnostic feature that could not be appreciated using solely 2D, even very high-resolution, seismic profiles. In addition, the comparison of bathymetric surveys gathered with one-year lapses shows the migration of subaqueous sand dunes on the clinothem topset, the formation of ephemeral cut-and-fill features at the rollover point (few m below mean sea level), the presence of collapse depressions derived by sagging of sediments and fluid expulsion (possibly induced by storm waves) on the foreset, and splays of sand likely reflecting gravity flows on the lower foreset. Though the modern Po Delta is anthropogenic in many respects, its subaqueous clinothem can be studied as a scale model for ancient clinothems that are less resolved geometrically and far less constrained chronologically. 相似文献
2.
This paper proposes a new methodological approach to silted reservoir management and defence, which combines the reservoir rehabilitation process and the utilization of the recovered water volumes and sediments. This approach, strategic from both the economical and environmental points of view, is here defined as Economic Environmental Defence (EED) of a reservoir. The EED approach is applied to the case study of Guardialfiera reservoir, where the available experimental data allowed the estimation of silta-tion up to date, the analysis of the distribution of sediment particle size along the reservoir bottom and the possibility to propose a feasible utilization of water and sediments resulting from the reservoir rehabilitation. 相似文献
3.
Annamaria Borriello Paolo Salucci 《Monthly notices of the Royal Astronomical Society》2001,323(2):285-292
We use high-quality optical rotation curves of nine low-luminosity disc galaxies to obtain the velocity profiles of the surrounding dark matter haloes. We find that they increase linearly with radius at least out to the edge of the stellar disc, implying that, over the entire stellar region, the density of the dark halo is about constant.
The properties of the mass structure of these haloes are similar to those found for a number of dwarf and low surface brightness galaxies, but provide a more substantial evidence of the discrepancy between the halo mass distribution predicted in the cold dark matter scenario and those actually detected around galaxies. We find that the density law proposed by Burkert reproduces the halo rotation curves, with halo central densities ( ρ0 ∼1–4×10−24 g cm−3 ) and core radii ( r 0 ∼5–15 kpc) scaling as ρ 0 ∝ r 0 −2/3 . 相似文献
The properties of the mass structure of these haloes are similar to those found for a number of dwarf and low surface brightness galaxies, but provide a more substantial evidence of the discrepancy between the halo mass distribution predicted in the cold dark matter scenario and those actually detected around galaxies. We find that the density law proposed by Burkert reproduces the halo rotation curves, with halo central densities ( ρ
4.
5.
Bruno MOLINO Rosa VIPARELLI Annamaria DE VINCENZO 《国际泥沙研究》2007,22(4):273-281
Knowledge of the morphological dynamics of a water course is essential for management of reservoir siltation. With an example of sedimentation in a reservoir in Basilicata, Italy, this paper demonstrates the effect on reservoir siltation of the hydraulic works, which are aimed to reduce sediment transport along the fluvial network and to prevent part of the sediment discharge from reaching the lake. The effect depends on the river type and on the the geological features of river basin slopes. The paper also shows how mass erosion can significantly contribute to development of reservoir siltation. Finally, preliminary results are provided about the time needed for river training works to be effective. 相似文献
6.
Genesis of zeolites in the Neapolitan Yellow Tuff: geological, volcanological and mineralogical evidence 总被引：1，自引：1，他引：0
Maurizio de'Gennaro Piergiulio Cappelletti Alessio Langella Annamaria Perrotta Claudio Scarpati 《Contributions to Mineralogy and Petrology》2000,139(1):17-35
The study proposes a model by which a thick succession of volcanic tuffs can be zeolitized by alteration of pyroclastic material
in the presence of sufficient eruptive water and at temperatures close to water vapour condensation. In the case of phreatomagmatic
products, the model simplifies interpretation of problematic deposits that exhibit pronounced vertical and lateral variation
in lithification grade. A major feature of the model is that thick zeolitized tuffs can be formed during emplacement of pyroclastic
products, in marked contrast to later alteration in an open hydrologic system. Geological, volcanological and mineralogical
data for the Neapolitan Yellow Tuff, a widespread trachytic pyroclastic deposit outcropping around Campi Flegrei (Southern
Italy), have been used to infer the physico-chemical conditions that determined mineral genesis. This tuff shows a reduction
in lithification grade towards the base, top and with distance from the vent and very variable zeolitization within the lithified
portion. We suggest that during initial emplacement the erupted products chilled against the ground, inhibiting zeolite crystallization.
During rapid deposition of the thick, wet succession thermal insulation allowed the persistence of elevated temperatures for
a time sufficient for enhancement of hydration-dissolution processes in the volcanic glass. The highly reactive alkali-trachytic
glass quickly buffered the acid pH of the system, favouring phillipsite crystallization followed by chabazite nucleation.
The variable zeolite content reflects fluctuating emplacement conditions (e.g. changes in water content and temperature).
Cooling of the upper and relatively thin distal deposits inhibited the zeolitization process, thereby preserving the primary
unlithified deposit.
Received: 25 May 1999 / Accepted: 28 October 1999 相似文献
7.
Redi Daniele Cannatelli Claudia Esposito Rosario Lima Annamaria Petrosino Paola De Vivo Benedetto 《Mineralogy and Petrology》2017,111(1):43-67
Mineralogy and Petrology - Clinopyroxene and olivine are ubiquitous phases in Somma-Vesuvius (SV) volcanics and for the first time they were systematically studied in several products younger than... 相似文献
8.
Research progress in volcanology in the Neapolitan area, southern Italy: a review and some alternative views 总被引：1，自引：0，他引：1
Benedetto De Vivo Paola Petrosino Annamaria Lima Giuseppe Rolandi Harvey E. Belkin 《Mineralogy and Petrology》2010,99(1-2):1-28
Comprehensive reviews are given for the major volcanic systems that occur in the greater metropolitan area of Naples, southern Italy; Mt. Somma-Vesuvius to the east and the Campi Flegrei volcanic system to the west. Also included in the review is a detailed discussion of the large, highly explosive Campania Volcanic Zone (CVZ) ignimbrite events. These volcanic areas have been studied for more than 100 years, yet significant differences of opinion exist related to fundamental issues of origin and distribution. We present some alternative views related to petrogenesis on some issues based on more than 25 years of research. The relationship between risk assessment and management that impacts the threatened society or culture and the past and ongoing fundamental volcanological research is an essential part of the science. Countries with limited resources may be forced to accept an increased risk but even highly industrialized societies may not be able to completely eliminate deaths from volcanic eruptions. Scientific studies of the hazardous regions should be comprehensive and include reasonable alternative interpretations as this information reveals the level of confidence that must be conveyed to the public officials. The authors review the state of the art of risk assessment and management of the volcanic hazards in the Neapolitan region in light of the review of research. 相似文献
9.
Ciro Del Negro Luigi Fortuna Alexis Herault Annamaria Vicari 《Bulletin of Volcanology》2008,70(7):805-812
Since the mechanical properties of lava change over time, lava flows represent a challenge for physically based modeling.
This change is ruled by a temperature field which needs to be modeled. MAGFLOW Cellular Automata (CA) model was developed
for physically based simulations of lava flows in near real-time. We introduced an algorithm based on the Monte Carlo approach
to solve the anisotropic problem. As transition rule of CA, a steady-state solution of Navier-Stokes equations was adopted
in the case of isothermal laminar pressure-driven Bingham fluid. For the cooling mechanism, we consider only the radiative
heat loss from the surface of the flow and the change of the temperature due to mixture of lavas between cells with different
temperatures. The model was applied to reproduce a real lava flow that occurred during the 2004–2005 Etna eruption. The simulations
were computed using three different empirical relationships between viscosity and temperature. 相似文献
10.
Cave clastic sediments as a tool for refining the study of human occupation of prehistoric sites: insights from the cave site of La Cala (Cilento,southern Italy) 
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