Susceptibility of intrusion-related landslides at volcanic islands: the Stromboli case study     

Federico Di Traglia  Stefania Bartolini  Erica Artesi  Teresa Nolesini  Andrea Ciampalini  Daniela Lagomarsino  Joan Martí  Nicola Casagli 《Landslides》2018,15(1):21-29

Susceptibility of intrusion-related landslides in an active volcano was evaluated coupling the landslide susceptibility estimation by random forest (RF), and the probabilistic volcanic vent opening distribution, as proxy for magma injection, using the QVAST tool. In order to develop and test the method proposed here, the RF/QVAST approach was adopted for Stromboli volcano (Southern Italy) since it experienced moderate to huge instability events, it is geomorphologically prone to instability events, and it is affected by active intense volcanic activity that can produce slope instability. The main destabilizing factors of the volcanic flanks are the slope, the aspect, the terrain roughness, the land cover and the litho-technical features of the outcropping rocks. Estimation of volcanic susceptibility shows that the areas with high probability of new vent opening are located in the north-western unstable volcano flank (Sciara del Fuoco), in the volcano summit and the north-eastern volcano flank coherent with the possible re-activation of the eruptive fissures related to the regional tectonic setting. The areas with higher probability of intrusion-related landslides are located in the upper part of the Sciara del Fuoco, while the rest of the island show moderate to low probability of intrusion-related landslide occurrence.  相似文献   

The First International Workshop on Warning Criteria for Active Slides: technical issues,problems and solutions for managing early warning systems   总被引：1，自引：0，他引：1  

Catherine Cloutier  Federico Agliardi  Giovanni Battista Crosta  Paolo Frattini  Corey Froese  Michel Jaboyedoff  Jacques Locat  Clément Michoud  Hideaki Marui 《Landslides》2015,12(1):205-212

  相似文献   

Morphometrical analysis of torrential flows-prone catchments in tropical and mountainous terrain of the Colombian Andes by machine learning techniques     

Arango  María Isabel  Aristizábal  Edier  Gómez  Federico 《Natural Hazards》2021,105(1):983-1012

Natural Hazards - Assessment of susceptibility to torrential flows at the catchment scale is a necessary step for prioritising zones that can be identified by hazard and risk maps. In the Andean...  相似文献   

Intrusion of shoshonitic magmas at shallow crustal depth: <Emphasis Type="Italic">T</Emphasis>–<Emphasis Type="Italic">P</Emphasis> path,H<Subscript>2</Subscript>O estimates,and AFC modeling of the Middle Triassic Predazzo Intrusive Complex (Southern Alps,Italy)     

Federico?CasettaEmail author  Massimo?Coltorti  Ryan?B.?Ickert  Costanza?Bonadiman  Pier?Paolo?Giacomoni  Theodoros?Ntaflos 《Contributions to Mineralogy and Petrology》2018,173(7):57

The multi-pulse shoshonitic Predazzo intrusive complex represents an ideal igneous laboratory for investigating the chemical and physical conditions of magma emplacement in a crustal context, since numerical models can be constrained by field evidence. It constitutes the most intriguing remnant of the Middle Triassic magmatic systems of the Dolomitic Area (Southern Alps), preserved by the Alpine tectonics. Predazzo Intrusive Complex comprises silica saturated (pyroxenites/gabbros to syenites), silica undersaturated (gabbros to syenites), and silica oversaturated (granites and syenogranites) rock suites. In this paper, we modeled its emplacement and evolution with a multiple thermo-/oxy-barometric, hygrometric, and EC-AFC approach. At odds with what proposed in literature but according to the field evidence, the emplacement of the Predazzo Intrusive Complex occurred at shallow depth (<?6 km). In this context, the different pulses differed slightly in bulk water content, but shared a common thermal regime, with temperatures between 1000 and 1100 °C and ~?600 °C at low-to-moderate oxidizing conditions (? 0.1 to +?0.7 ΔFMQ). The interaction between the intrusion and the shallow crustal rocks was minimal, with Sr and Nd isotopic compositions indicating an average of 5–6% assimilation of crust. A thermo- and oxy-barometric comparison with the nearby Mt. Monzoni also enabled to speculate about the solidification time of the intrusion, which we infer took place over about 700 ka.  相似文献   

Petrological evolution of the Middle Triassic Predazzo Intrusive Complex,Italian Alps   总被引：2，自引：0，他引：2  

Federico Casetta  Massimo Coltorti  Elena Marrocchino 《International Geology Review》2018,60(8):977-997

The Predazzo Intrusive Complex (PIC), a Ladinian plutonic body located in the Southern Alps (NE Italy), is made up of a 4.5 km³ gabbroic to syenitic and syenogranitic intrusion, basaltic to latitic volcanic products (about 6 km³ in volume) and by an extended dike swarm intruding both intrusive and volcanic rocks. An extensive field survey of the complex, followed by detailed petrographic and geochemical analyses, allowed the identification of three different magmatic units: a Shoshonitic Silica Saturated Unit (SS), 3.1 km³ in volume, a Shoshonitic Silica Undersaturated Unit (SU), 0.3 km³ in volume, and a Granitic Unit (GU), 1.1 km³ in volume. K-affinity, marked Nb and Ti negative anomalies and a strong Pb enrichment are distinctive markers for all PIC lithotypes. A general HFSE (Th, U, Pb), LREE (La, Ce, Pr, Nd) and Na enrichment characterizes the SU suite with respect to the SS series. Mass balance calculations, based on major and trace element whole rock and mineral compositions, have been used to simulate the fractionation process of SS and SU suites, showing (i) the complexity of the evolutionary stages of the PIC and (ii) the analogy between the calculated subtracted solid assemblages and the natural cumulitic lithotypes outcropping in the area. The field relationships between the various portions of the intrusive complex, the volcanic products and the dike swarm define the temporal evolution of the PIC, in which the SS magma batch was followed by the GU and later on by the SU intrusion. The presence, in both eastern and western portions of the complex, of a transitional magmatic contact between the intrusive rocks of the SS suite and the volcanics is not in favour of the hypothesis of a caldera collapse to explain the ring-like shape of the PIC.  相似文献   

Primary dolomite in the Late Triassic Travenanzes Formation,Dolomites, Northern Italy: Facies control and possible bacterial influence          下载免费PDF全文

Nereo Preto  Anna Breda  Jacopo Dal Corso  Christoph Spötl  Federico Zorzi  Silvia Frisia 《Sedimentology》2015,62(3):697-716

In the late Carnian (Late Triassic), a carbonate‐clastic depositional system including a distal alluvial plain, flood basin and sabkha, tidal flat and shallow carbonate lagoon was established in the Dolomites (Northern Italy). The flood basin was a muddy supratidal environment where marine carbonates and continental siliciclastics interfingered. A dolomite phase made of sub‐micrometre euhedral crystals with a mosaic microstructure of nanometre‐scale domains was identified in stromatolitic laminae of the flood basin embedded in clay. This dolomite is interpreted here as primary and has a nearly stoichiometric composition, as opposed to younger early diagenetic (not primary) dolomite phases, which are commonly calcian. This primary dolomite was shielded from later diagenetic transformation by the clay. The stable isotopic composition of dolomite was analyzed along a depositional transect. The δ¹³C values range between ca ?6‰ and +4‰, with the most ¹³C‐depleted values in dolomites of the distal alluvial plain and flood basin, and the most ¹³C‐enriched in dolomites of the tidal flat and lagoon. Uniform δ¹⁸O values ranging between 0‰ and +3‰ were found in all sedimentary facies. It is hypothesized that the primary dolomite with mosaic microstructure nucleated on extracellular polymeric substances secreted by sulphate reducing bacteria. A multi‐step process involving sabkha and reflux dolomitization led to partial replacement and overgrowth of the primary dolomite, but replacement and overgrowth were facies‐dependent. Dolomites of the landward, clay‐rich portion of the sedimentary system were only moderately overgrown during late dolomitization steps, and partly retain an isotopic signature consistent with bacterial sulphate reduction with δ¹³C as low as ?6‰. In contrast, dolomites of the marine, clay‐free part of the system were probably transformed through sabkha and reflux diagenetic processes into calcian varieties, and exhibit δ¹³C values of ca +3‰. Major shifts of δ¹³C values strictly follow the lateral migration of facies and thus mark transgressions and regressions.  相似文献   

Long‐term comparison of structure and dynamics of the red coral metapopulation of the Portofino Promontory (Ligurian Sea): a case‐study for a Marine Protected Area in the Mediterranean Sea          下载免费PDF全文

Giorgio Bavestrello  Marzia Bo  Marco Bertolino  Federico Betti  Riccardo Cattaneo‐Vietti 《Marine Ecology》2015,36(4):1354-1363

A large amount of data on the precious coral Corallium rubrum has attested to a dramatic shift in the size structure of its over‐harvested Mediterranean populations in recent decades. One of the main problems for the conservation of this species is the substantial lack of data concerning the time span necessary for a population subjected to pluri‐decennial harvesting pressure to return to its pristine status. Here, we present a multi‐annual data set gathered from the Marine Protected Area (MPA) of Portofino, which hosts the most important shallow‐water coral populations in the Ligurian Sea and was subjected to strong harvesting pressure from the 1950s to the early 1970s. Quantitative comparison of the population structure data recorded in 1964, 1990 and 2012 indicated a strong size increase of the colonies (from 3 to 8 g mean weight), resulting in an increase in colony biomass from 300 to the current 1500 g·m^?2. As a consequence, over the same span of time, the density of colonies has slightly decreased. The role of mass mortality phenomena, like that occurred in this area during 1999, as possible biological features triggering the switch of red coral populations from a ‘grass plain‐like’ towards a ‘forest‐like’ structure, is discussed. All these data indicate that the instigation of MPAs is a winning strategy in the conservation of this precious species and similar management plans should also be evaluated for the protection of the deep benthic communities thriving on off‐shore banks.  相似文献   

Decoupled kinematics of two neighbouring permafrost creeping landforms in the Eastern Italian Alps     

Roberto Seppi  Luca Carturan  Alberto Carton  Thomas Zanoner  Matteo Zumiani  Federico Cazorzi  Aldo Bertone  Carlo Baroni  Maria Cristina Salvatore 《地球表面变化过程与地形》2019,44(13):2703-2719

An overall acceleration of rock glacier displacement rates in the Alps has been observed in recent decades, with several cases of destabilization leading to potential geomorphological hazards. This behaviour has been attributed to the rising permafrost temperature, induced by atmospheric warming and regulated by thermo-hydrological processes. Landforms derived from the interaction of glacier remnants and permafrost are widespread in mountain areas, but are less studied and monitored than talus rock glaciers. This work presents a comparative study of a talus rock glacier and a glacial-permafrost composite landform (GPCL) in the Eastern Italian Alps. The two landforms are only 10 km apart, but have rather different elevation ranges and main slope aspects. The kinematics and ground thermal conditions were monitored from 2001 to 2015 along with geomorphological surveys, analyses of historical maps and remote sensing data. The dynamic behaviour of the rock glacier was similar to the majority of monitored rock glaciers in the Alps, with an acceleration after 2008 and a velocity peak in 2015. In contrast, the GPCL had a nearly unchanged displacement rate during the observation period. Statistical analyses of kinematic vs. nivo-meteorological variables revealed a dynamic decoupling of the two landforms after 2008 that corresponds with increased winter snow accumulation. Although the kinematics of both landforms respond to ground surface temperature variations, the collected evidence suggests a different reaction of ground surface temperature to variations in the precipitation regime. This different reaction is likely due to local topo-climatic conditions that affect snow redistribution by wind. The different reactions of the two systems to the same climatic forcing is likely a legacy of their different origins. GPCL dynamics result from interaction of permafrost and residual glacial dynamics that are associated with possible peculiarities in the internal/basal meltwater circulation, whose future response is uncertain and requires improved understanding. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd.  相似文献   

Keratose-dominated sponge grounds from temperate mesophotic ecosystems (NW Mediterranean Sea)     

Francesco Enrichetti  Giorgio Bavestrello  Federico Betti  Martina Coppari  Margherita Toma  Roberto Pronzato  Simonepietro Canese  Marco Bertolino  Gabriele Costa  Maurizio Pansini  Marzia Bo 《Marine Ecology》2020,41(6):e12620

Differently from the North Atlantic Ocean, only few examples of sponge grounds are known from the Mediterranean Sea, mainly thriving in the deep sea. In this study, a novel temperate mesophotic ecosystem dominated by massive keratose sponges is reported from the Ligurian deep continental shelf. An extensive Remotely Operated Vehicle (ROV) survey allowed to study the structure and large-scale distribution of this biocoenosis. The sponge grounds here described are highly fragmented, being formed by a large number of dense, discrete aggregations of Sarcotragus foetidus (up to 7.7 specimens/m²) and other sponges, including Spongia lamella and Axinella polypoides. They mainly occur on flat, patchy and highly silted hardgrounds between 40 and 70 m depth. These sponge-dominated ecosystems have an exceptionally wide spatial distribution, estimated to cover up to nearly 200 hectares, with the largest sponge grounds occurring along the westernmost part of the Ligurian coast, probably in relation to more suitable oceanographic conditions. The dominant sponge species reach considerable heights (up to 65 cm), greatly increasing the habitat three-dimensionality and acting as poles of attraction for a diverse sessile and vagile fauna. In addition, the high abundance of the keratose sponge grounds at mesophotic depths might represent a larval source for shallow-water populations that in the last decades have been stricken by several mass mortality events.  相似文献   

Forecasting Solar Flares Using Magnetogram-based Predictors and Machine Learning     

Kostas Florios  Ioannis Kontogiannis  Sung-Hong Park  Jordan A. Guerra  Federico Benvenuto  D. Shaun Bloomfield  Manolis K. Georgoulis 《Solar physics》2018,293(2):28

We propose a forecasting approach for solar flares based on data from Solar Cycle 24, taken by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) mission. In particular, we use the Space-weather HMI Active Region Patches (SHARP) product that facilitates cut-out magnetograms of solar active regions (AR) in the Sun in near-realtime (NRT), taken over a five-year interval (2012?–?2016). Our approach utilizes a set of thirteen predictors, which are not included in the SHARP metadata, extracted from line-of-sight and vector photospheric magnetograms. We exploit several machine learning (ML) and conventional statistics techniques to predict flares of peak magnitude \({>}\,\mbox{M1}\) and \({>}\,\mbox{C1}\) within a 24 h forecast window. The ML methods used are multi-layer perceptrons (MLP), support vector machines (SVM), and random forests (RF). We conclude that random forests could be the prediction technique of choice for our sample, with the second-best method being multi-layer perceptrons, subject to an entropy objective function. A Monte Carlo simulation showed that the best-performing method gives accuracy \(\mathrm{ACC}=0.93(0.00)\), true skill statistic \(\mathrm{TSS}=0.74(0.02)\), and Heidke skill score \(\mathrm{HSS}=0.49(0.01)\) for \({>}\,\mbox{M1}\) flare prediction with probability threshold 15% and \(\mathrm{ACC}=0.84(0.00)\), \(\mathrm{TSS}=0.60(0.01)\), and \(\mathrm{HSS}=0.59(0.01)\) for \({>}\,\mbox{C1}\) flare prediction with probability threshold 35%.  相似文献