Trends in cpue and related changes in spatial distribution of demersal fish species in the Kattegat and Skagerrak, eastern North Sea, between 1981 and 2003     

Casini  Michele; Cardinale  Massimiliano; Hjelm  Joakim; Vitale  Francesca 《ICES Journal of Marine Science》2005,62(4):671-682

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Three-dimensional,time-dependent modeling of rainfall-induced landslides over a digital landscape: a case study     

The Viet Tran  Massimiliano Alvioli  Giha Lee  Hyun Uk An 《Landslides》2018,15(6):1071-1084

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Tectonically driven deposition and landscape evolution within upland incised valleys: Ambra Valley fill,Pliocene–Pleistocene,Tuscany, Italy          下载免费PDF全文

Valeria Bianchi  Massimiliano Ghinassi  Mauro Aldinucci  Jacopo Boaga  Andrea Brogi  Rita Deiana 《Sedimentology》2015,62(3):897-927

Sedimentation in the upstream reaches of incised valleys is predominantly of alluvial origin and, in most cases, independent from relative sea‐level or lake‐level oscillations. Preserved facies distributions record the depositional response to a combination of allogenic factors, including tectonics, climate and landscape evolution. Tectonics drive fluvial aggradation and degradation through local changes in gradient, both longitudinal and transverse to the valley slope. This article deals with a Pliocene–Pleistocene fluvial valley fill developed in the north‐eastern shoulder of the Siena Basin (Northern Apennines, Italy). Evolution of the valley was not influenced by sea‐level or lake‐level changes and morphological and depositional evolution of valley resulted from extensional tectonics that gave rise to normal and oblique‐slip faults orthogonal and parallel to the valley axis. Data from both field observations and geophysical study are interpreted to develop a comprehensive tectono‐sedimentary model of coeval longitudinal and lateral tilting of the developing alluvial plain. Longitudinal tilting was generated by a transverse, upstream‐dipping normal fault that controlled the aggradation of fining‐upward strata sets. Upstream of the fault zone, valley back‐filling generated an architecture similar to that of classic, sea‐level‐controlled, coastal incised valleys. Downstream of the fault zone, valley down‐filling was related to an overwhelming sediment supply sourced and routed from the active fault zone itself. Lateral tilting was promoted by the activity of a fault oriented parallel to the valley axis, as well as by different offsets along near orthogonal faults. As a result, the valley trunk system experienced complex lateral shifts, which were governed by interacting fault‐generated subsidence and by the topographic confinement of progradational, flank‐sourced alluvial fans.  相似文献   

Gilbert‐type deltas recording short‐term base‐level changes: Delta‐brink morphodynamics and related foreset facies          下载免费PDF全文

Katarina Gobo  Massimiliano Ghinassi  Wojciech Nemec 《Sedimentology》2015,62(7):1923-1949

Gilbert‐type deltas are sensitive recorders of short‐term base‐level changes, but the delta‐front record of a base‐level rise tends to be erased by fluvial erosion during a subsequent base‐level fall, which renders the bulk record of base‐level changes difficult to decipher from the delta‐front deposits. The present detailed study of three large Pleistocene Gilbert‐type deltas uplifted on the southern coast of the Gulf of Corinth, Greece, indicates a genetic link between the delta‐front morphodynamic responses to base‐level changes and the delta‐slope sedimentation processes. Sigmoidal delta‐brink architecture signifies a base‐level rise and is accompanied by a debrite‐dominated assemblage of delta foreset deposits, thought to form when the aggrading delta front stores sediment and undergoes discrete gravitational collapses. Oblique delta‐brink architecture tends to be accompanied by a turbidite‐dominated assemblage of foreset deposits, which are thought to form when the delta‐front accommodation decreases and the sediment carried by hyperpycnal effluent bypasses the front. This primary signal of the system response to base‐level changes combines further with the secondary ‘noise’ of delta autogenic variation and possible allogenic fluctuations in fluvial discharge due to regional climatic conditions. Nevertheless, the evidence suggests that the facies trends of delta foreset deposits may be used to decipher the delta ‘hidden’ record of base‐level changes obliterated by fluvial topset erosion. Early‐stage bayhead deltas may be an exception from the hypothetical model, because their narrow front tends to be swept by river floods irrespective of base‐level behaviour and their subaqueous slope deposits are thus mainly turbidites.  相似文献   

LIDAR strip adjustment: Application to volcanic areas     

Massimiliano Favalli  Alessandro Fornaciai  Maria Teresa Pareschi 《Geomorphology》2009,111(3-4):123-135

DEMs derived from LIDAR data are nowadays largely used for quantitative analyses and modelling in geology and geomorphology. High-quality DEMs are required for the accurate morphometric and volumetric measurement of land features. We propose a rigorous automatic algorithm for correcting systematic errors in LIDAR data in order to assess sub-metric variations in surface morphology over wide areas, such as those associated with landslide, slump, and volcanic deposits. Our procedure does not require a priori knowledge of the surface, such as the presence of known ground control points. Systematic errors are detected on the basis of distortions in the areas of overlap among different strips. Discrepancies between overlapping strips are assessed at a number of chosen computational tie points. At each tie point a local surface is constructed for each strip containing the point. Displacements between different strips are then calculated at each tie point, and minimization of these discrepancies allows the identification of major systematic errors. These errors are identified as a function of the variables that describe the data acquisition system. Significant errors mainly caused by a non-constant misestimation of the roll angle are highlighted and corrected. Comparison of DEMs constructed using first uncorrected and then corrected LIDAR data from different Mt. Etna surveys shows a meaningful improvement in quality: most of the systematic errors are removed and the accuracy of morphometric and volumetric measurements of volcanic features increases. These corrections are particularly important for the following studies of Mt. Etna: calculation of lava flow volume; calculation of erosion and deposition volume of pyroclastic cones; mapping of areas newly covered by volcanic ash; and morphological evolution of a portion of an active lava field over a short time span.  相似文献   

Seismic expression of active extensional faults in northern Umbria (Central Italy)     

Cristiano Collettini  Massimiliano Barchi  Cristina Pauselli  Costanzo Federico  Giampaolo Pialli 《Journal of Geodynamics》2000,29(3-5)

This paper deals with the geometry and kinematics of the active normal faults in northern Umbria, and their relationship with the seismicity observed in the area. In particular, we illustrate the contribution of seismic reflection data (a network of seismic profiles, NNW–SSE and WSW–ENE trending) in constraining at depth the geometry of the different active fault systems and their reciprocal spatial relationships. The main normal fault in the area is the Alto Tiberina fault, NNW trending and ENE dipping, producing a displacement of about 5 km, and generating a continental basin (Val Tiberina basin), infilled by up to 1500 m with Upper Pliocene–Quaternary deposits. The fault has a staircase trajectory, and can be traced on the seismic profiles to a depth of about 13 km. A set of WSW-dipping, antithetic faults can be recognised on the profiles, the most important of which is the Gubbio fault, bordering an extensional Quaternary basin and interpreted as an active fault based on geological, geomorphologic and seismological evidence. The epicentral distribution of the main historical earthquakes is strictly parallel to the general trend of the normal faults. The focal mechanisms of the major earthquakes show a strong similarity with the attitude of the extensional faults, mapped at the surface and recognised on the seismic profiles. These observations demonstrate the connection between seismicity in the area and the activity of the normal faults. Moreover, the distribution of the instrumental seismicity suggests the activity of the Alto Tiberina fault as the basal detachment for the extensional tectonics of the area. Finally, the action of the Alto Tiberina fault was simulated using two dimensional finite element modelling: a close correspondence between the concentration of shear stresses in the model and the distribution of the present earthquakes was obtained.  相似文献   

Changes in the wind-wave field and related salt-marsh lateral erosion: inferences from the evolution of the Venice Lagoon in the last four centuries     

Laura Tommasini  Luca Carniello  Massimiliano Ghinassi  Marcella Roner  Andrea D'Alpaos 《地球表面变化过程与地形》2019,44(8):1633-1646

Salt marshes are crucially important ecosystems at the boundary between the land and the sea, that are experiencing significant losses worldwide mainly dictated by the erosion of their margins. Improving our understanding of the mechanisms controlling marsh edge erosion is a key step to address conservation issues and salt-marsh response to changes in the environmental forcing. Here we have employed a complete, coupled Wind-Wave Tidal Model (WWTM) to analyse the temporal evolution of the wave field, and in particular of the mean wave-power density, in the Venice Lagoon over the past four centuries (from 1611 to 2012). We have then related wave-field changes to the observed erosion patterns determined by comparing recent aerial photographs (1978–2010) and historical bathymetric data. The results of our analyses from the Venice Lagoon show that, while wave-fields did not significantly change from 1611 to 1901, a rapid increase in wave-power densities occurred in the last century. This is suggested to depend on the positive feedback between relevant morphological evolutions and changes in the wave field, both influenced by natural forcing and anthropogenic pressures. We also emphasize the existence of a strong positive linear relationship between the volumetric marsh erosion rate and mean wave-power density. We thus suggest that relating salt-marsh lateral erosion rates to properly computed mean wave-power densities provides a valuable tool to address long-term tidal morphodynamics. © 2019 John Wiley & Sons, Ltd.  相似文献   

Shaking table tests on a masonry building monitored using smart bricks: Damage detection and localization     

Andrea Meoni  Antonella D'Alessandro  Nicola Cavalagli  Massimiliano Gioffré  Filippo Ubertini 《地震工程与结构动力学》2019,48(8):910-928

The seismic behavior of unreinforced masonry buildings is typically characterized by premature brittle collapse mechanisms that can cause serious consequences for the protection of human lives and for the preservation of historical and cultural heritage. Structural health monitoring can be a powerful tool enabling a quick post-earthquake assessment of the structure's performance, but its applications are still scarce as a consequence of the severe limitations affecting off-the-shelf sensing technologies, in terms of local nature of the measurements, costs, as well as long-term behavior, installation, and maintenance. To overcome some of these limitations, the authors have recently proposed a new sensing technology, called “smart brick,” that is a durable clay brick doped with stainless steel microfibers, working as a smart strain sensor for masonry buildings. This paper presents the first full-scale application of smart bricks, used for detecting and localizing progressive earthquake-induced damage in an unreinforced masonry building subjected to shaking table tests. Smart bricks are employed to detect changes in load paths on masonry walls, comparing strain measurements acquired after each step of the seismic sequence with those referring to the undamaged structure. Experimental results are interpreted using a 3D finite element model built to reproduce the shaking table tests. Overall, the results demonstrate that the smart bricks can effectively reveal local permanent changes in structural conditions following a progressive damage, therefore being apt for earthquake-induced damage detection and localization.  相似文献   

Numerical Investigation of a Methane Leakage from a Geothermal Well into a Shallow Aquifer     

Andrea D'Aniello  Massimiliano Fabbricino  Daniela Ducci  Domenico Pianese 《Ground water》2020,58(4):598-610

The potential environmental impacts on subsurface water resources induced by unconventional gas production are still under debate. Solving the controversy regarding the potential adverse effects of gas leakages on groundwater resources is therefore crucial. In this work, an interesting real-world case is presented in order to give further insight into methane multiphase and transport behavior in the shallow subsurface, often disregarded compared to the behavior in the deep subsurface. Multiphase flow and solute transport simulations were performed to assess the vulnerability of an existing shallow unconfined aquifer with respect to a hypothetical methane leakage resulting from a well integrity failure of a former deep geothermal well. The analysis showed that migration of gaseous methane through the aquifer under examination can be extremely fast (of the order of a few minutes), occurring predominantly vertically upwards, close to the well. By contrast, dissolved methane migration is largely affected by the groundwater flow field and occurs over larger time scales (of the order of months/years), covering a greater distance from the well. Overall, the real concern for this site in case of gas leakages is the risk of explosion in the close vicinity of the well. Predicted maximum gaseous fluxes (0.89 to 22.60 m³/d) are comparable to those reported for leaking wells, and maximum dissolved methane concentrations may overcome risk mitigation thresholds (7 to 10 mg/L) in a few years. Therefore, surface and subsurface monitoring before decommissioning is strongly advised to ensure the safety of the site.  相似文献   

The 2013 European Seismic Hazard Model: key components and results   总被引：11，自引：5，他引：6  

Jochen Woessner  Danciu Laurentiu  Domenico Giardini  Helen Crowley  Fabrice Cotton  Gottfried Grünthal  Gianluca Valensise  Ronald Arvidsson  Roberto Basili  Mine Betül Demircioglu  Stefan Hiemer  Carlo Meletti  Roger W. Musson  Andrea N. Rovida  Karin Sesetyan  Massimiliano Stucchi  The SHARE Consortium 《Bulletin of Earthquake Engineering》2015,13(12):3553-3596

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