Modeling ground deformations of Panarea volcano hydrothermal/geothermal system (Aeolian Islands, Italy) from GPS data   总被引：1，自引：0，他引：1  

Alessandra Esposito  Marco Anzidei  Simone Atzori  Roberto Devoti  Guido Giordano  Grazia Pietrantonio 《Bulletin of Volcanology》2010,72(5):609-621

Panarea volcano (Aeolian Islands, Italy) was considered extinct until November 3, 2002, when a submarine gas eruption began in the area of the islets of Lisca Bianca, Bottaro, Lisca Nera, Dattilo, and Panarelli, about 2.5 km east of Panarea Island. The gas eruption decreased to a state of low degassing by July 2003. Before 2002, the activity of Panarea volcano was characterized by mild degassing of hydrothermal fluid. The compositions of the 2002 gases and their isotopic signatures suggested that the emissions originated from a hydrothermal/geothermal reservoir fed by magmatic fluids. We investigate crustal deformation of Panarea volcano using the global positioning system (GPS) velocity field obtained by the combination of continuous and episodic site observations of the Panarea GPS network in the time span 1995–2007. We present a combined model of Okada sources, which explains the GPS results acquired in the area from December 2002. The kinematics of Panarea volcano show two distinct active crustal domains characterized by different styles of horizontal deformation, supported also by volcanological and structural evidence. Subsidence on order of several millimeters/year is affecting the entire Panarea volcano, and a shortening of 10⁻⁶ year⁻¹ has been estimated in the Islets area. Our model reveals that the degassing intensity and distribution are strongly influenced by geophysical-geochemical changes within the hydrothermal/geothermal system. These variations may be triggered by changes in the regional stress field as suggested by the geophysical and volcanological events which occurred in 2002 in the Southern Tyrrhenian area.  相似文献   

Investigating on the 1920 Garfagnana earthquake (M_w=6.5): Evidences of site effects in Villa Collemandina (Tuscany,Italy)     

Roberto De Ferrari  Gabriele Ferretti  Simone Barani  Daniele Spallarossa 《Soil Dynamics and Earthquake Engineering》2010

This paper presents a comprehensive ground response study for the municipality of Villa Collemandina in Northern Tuscany (Italy). This site was selected following a macroseismic analysis of the 1920 Garfagnana earthquake (M_w=6.5), which, at Villa Collemandina, produced damage and losses that were larger than at any other site near the earthquake epicentre, thus indicating the presence of possible site effects. Hence, both experimental and numerical methods are applied in order to investigate the ground response at different locations within the Villa Collemandina municipality. Results obtained from the spectral analysis of earthquake recordings using the reference site method and those from a 2-dimensional dynamic simulation reveal the presence of site effects due to the buried geomorphology (basin-like effects), allowing us to explain the severe damage and losses produced by the 1920 Garfagnana earthquake. As a further result, horizontal to vertical spectral ratio techniques and 1D soil modelling are proved to be inadequate for an effective characterization of the ground response at sites that, like Villa Collemandina, present a complex local geology.  相似文献   

First attempts towards an integrative concept for the ecological assessment of groundwater ecosystems   总被引：1，自引：0，他引：1  

Christian Steube  Simone Richter  Christian Griebler 《Hydrogeology Journal》2009,17(1):23-35

Healthy aquifers deliver important ecosystem services, e.g. the purification of infiltrating water and the storage of high-quality water over decades in significant quantities. The functioning of terrestrial and surface aquatic ecosystems directly depends on groundwater and vice versa. Nowadays, legislation has started to consider groundwater not only as a resource but as a living ecosystem. The assessment of ecosystems requires consideration of ecological criteria, which, so far, are not available for groundwater systems. In the framework of a project supported by the German Federal Environment Agency (UBA), a first concept for the ecological assessment of groundwater ecosystems is developed. Steps to be taken are introduced, with a strong focus on microbes as potential bioindicators. These include (1) the typology of groundwater ecosystems, (2) the derivation of natural background values, (3) the identification of potential bioindicators, and (4) the development of an assessment model. First successes and difficulties associated with these challenges, e.g. the lack of simple correlations between abiotic and biotic variables, are discussed on the basis of a data set from a local and regional aquifer in NE Germany. The need for collaboration between ecologists, hydrogeologists and geochemists, as well as the application of modern approaches such as multivariate statistics, is emphasized.  相似文献   

Environmental heterogeneity affects input, storage, and transformation of coarse particulate organic matter in a floodplain mosaic     

Simone Daniela Langhans  Urs Richard  Janine Rueegg  Urs Uehlinger  Peter Edwards  Michael Doering  Klement Tockner 《Aquatic Sciences - Research Across Boundaries》2013,75(3):335-348

Quantifying spatial and temporal dynamics of organic matter (OM) is critical both for understanding ecosystem functioning and for predicting impacts of landscape change. To determine the influence of different habitats and coarse particulate OM (CPOM) types upon floodplain OM dynamics, we quantified aerial input, lateral surface transfer, and surface storage of CPOM over an annual cycle on the near-natural floodplain of the River Tagliamento in NE-Italy. Using these data, we modelled floodplain leaf dynamics, taking account of the spatial distribution and hydrologic connectivity of habitats, and using leaf storage as a response variable. Mean aerial CPOM input to the floodplain was similar from riparian forest and islands, but surface transfer was greater from islands, supporting the suggestion that these habitats act as “islands of fertility” along braided rivers. Leaves were the lateral conveyor of energy to more open parts of the floodplain, whereas CPOM was mainly stored as small wood in vegetated islands and riparian forest. Simulating the loss of habitat diversity (islands, ponds) decreased leaf storage on the whole floodplain, on exposed gravel and in large wood accumulations. In contrast, damming (loss of islands, ponds and floods plus floodplain overgrowth) greatly increased storage on exposed gravel. A random shuffle of habitats led to a storage increase on exposed gravel, while that in large wood accumulations and ponds declined. These results disentangle some of the complexities of CPOM dynamics in floodplain ecosystems, illustrate the value of models in understanding ecosystem functioning at a landscape level, and directly inform river management practice.  相似文献   

Geochemical evidence of the 8.2 ka event and other Holocene environmental changes recorded in paleolagoon sediments,southeastern Brazil     

Alethéa E.M. Sallun  William Sallun Filho  Kenitiro Suguio  Marly Babinski  Simone M.C.L. Gioia  Benjamin A. Harlow  Wania Duleba  Paulo E. De Oliveira  Maria Judite Garcia  Cinthia Z. Weber  Sérgio R. Christofoletti  Camilla da S. Santos  Vanda B. de Medeiros  Juliana B. Silva  Maria Cristina Santiago-Hussein  Rosana S. Fernandes 《Quaternary Research》2012,77(1):31-43

The paleoclimatic record of Juréia Paleolagoon, coastal southeastern Brazil, includes cyclic and gradual changes with different intensities and frequencies through geological time, and it is controlled by astronomical, geophysical, and geological phenomena. These variations are not due to one single cause, but they result from the interaction of several factors, which act at different temporal and spatial scales. Here, we describe paleoenvironmental evidence regarding climatic and sea level changes from the last 9400 cal yr BP at the Juréia Paleolagoon — one of the main groups of protected South Atlantic ecosystems. Geochemical evidences were used to identify anomalies from multi-proxy analyses of a paleolagoon sediment core. The anomalies of centennial scale were correlated to climate and transgression–regression cycles from the Holocene period. Decadal scale anomalous oscillations in the Quaternary paleolagoon sediments occur between 9400 and 7500 cal yr BP, correlated with long- and short-term natural events, which generated high sedimentation rates, mainly between 8385 and 8375 cal yr BP (10 cm/yr). Our results suggest that a modern-day short-duration North Atlantic climatic event, such as the 8.2 ka event, could affect the environmental equilibrium in South America and intensify the South American Summer Monsoon.  相似文献   

3D modeling of light interception in heterogeneous forest canopies using ground-based LiDAR data     

Dimitry Van der Zande  Jan Stuckens  Willem W. Verstraeten  Simone Mereu  Bart Muys  Pol Coppin 《International Journal of Applied Earth Observation and Geoinformation》2011

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Exploring the orientations which characterise the likely public acceptance of low emission energy technologies     

Simone Carr-Cornish  Peta Ashworth  John Gardner  Stephen J. Fraser 《Climatic change》2011,107(3-4):549-565

There is a large body of research and development into the low emission energy technologies that has the potential to assist developed and developing countries transition to more sustainable energy systems. It has long been recognised that public perceptions can have a fundamental effect on the market for technology and this issue raises questions about the role society will play in developing a low emissions energy future. Understanding how the public will respond to the range of low emission energy technologies as part of a climate change mitigation package is therefore critical for researchers, policy makers and industry stakeholders. In the current research, we investigated the Australian public’s likely acceptance of a range of low emission energy technologies by assessing the diverse ‘orientations’ that have emerged in response to low emission energy technologies. In a survey of two Australian states we measured the support for, and knowledge of, a range of low emission energy technologies. Using self-organising maps, a relatively new approach for segmenting response profiles, we identified that at least four distinct ‘orientations’ have emerged toward the issue and are characterising the likely acceptance of these technologies: ‘Disengaged’, ‘Nuclear Oriented’, ‘Renewables Oriented’, and ‘Engaged’. The implications of these multiple public viewpoints are described for climate change mitigation policy and for future research into the social acceptance of alternative energy technologies.  相似文献   

Five years of thermal intra-urban monitoring in Florence (Italy) and application of climatological indices     

Martina Petralli  Luciano Massetti  Simone Orlandini 《Theoretical and Applied Climatology》2011,104(3-4):349-356

This paper presents 5?years of detailed intra-urban thermal measurements carried out in Florence (Italy) by a network of 25 air temperature stations. Daily, hourly, and degree-day indices were applied to hourly data to evaluate the difference within the complex urban environment of Florence. Stations were grouped in four clusters with similar thermal regimes in each season. Our results evidence a mean difference of almost 2°C between the hottest and the coolest cluster in all seasons. Furthermore, the coolest cluster had on average more than ten frost days in winter and the hottest cluster more than 12 summer days in summer. The intra-urban difference of tropical nights was even more evident, with values of 42 versus 10?days between the hottest and the coolest cluster during the summer period. The results of this study contribute to quantify the thermal intra-urban differences in the city of Florence, suggesting important applications in plant phenology, aerobiology, human health, urban planning, and biometeorology.  相似文献   

Multiplatform observation of the surface circulation in the Gulf of Naples (Southern Tyrrhenian Sea)   总被引：1，自引：1，他引：0  

Marco Uttieri  Daniela Cianelli  Bruno Buongiorno Nardelli  Berardino Buonocore  Pierpaolo Falco  Simone Colella  Enrico Zambianchi 《Ocean Dynamics》2011,61(6):779-796

The Gulf of Naples (Southern Tyrrhenian Sea) is a highly urbanised area, where human activities and natural factors (e.g. river runoff, exchanges with adjacent basins) can strongly affect the water quality. In this work we show how surface transport can influence the distribution of passively drifting surface matter, and more in general if and how the circulation in the basin can promote the renovation of the surface layer. To this aim, we carried out a multiplatform analysis by putting together HF radar current fields, satellite images and modelling tools. Surface current fields and satellite images of turbidity patterns were used to initialise and run model simulations of particle transport and diffusion. Model results were then examined in relation to the corresponding satellite distributions. This integrated approach permits to investigate the concurrent effects of surface dynamics and wind forcing in determining the distribution of passive tracers over the basin of interest, identifying key mechanisms supporting or preventing the renewal of surface waters as well as possible areas of aggregation and retention.  相似文献   

Sr-Nd-Pb isotopes from the Radicofani Volcano, Central Italy: constraints on heterogeneities in a veined mantle responsible for the shift from ultrapotassic shoshonite to basaltic andesite magmas in a post-collisional setting     

Sandro Conticelli  Riccardo Avanzinelli  Sara Marchionni  Simone Tommasini  Leone Melluso 《Mineralogy and Petrology》2011,103(1-4):123-148

The Radicofani Volcano is characterised by few lava flows, a cinder cone and a denudated neck, and is part of the Tuscan Magmatic Province, the northernmost volcanic region of the Italian peninsula. In spite of the short time span of activity, a large time-dependant chemical and isotopic variability is observed. Most of the rocks of the Radicofani volcano are ultrapotassic shoshonites associated to younger basaltic andesites, found at the bottom of the neck. K₂O contents are positively correlated with trace element and isotopic variations. Shoshonitic and high-K calc-alkaline rocks of the Radicofani volcano are significantly different from shoshonites occurring in association with leucite-bearing ultrapotassic rocks in the southernmost portion of the Roman Magmatic Province. The studied rocks are characterised by high, but variable, levels of incompatible trace elements with a subduction-related signature, with troughs at Ba, Ta, Nb, and Ti, and peaks at Cs, K, Th, U, and Pb. Initial values of ⁸⁷Sr/⁸⁶Sr range from 0.71333 to 0.71588, ¹⁴³Nd/¹⁴⁴Nd ranges from 0.512050 to 0.512183, while the lead isotope ratios vary between 18.672 and 18.716 for ²⁰⁶Pb/²⁰⁴Pb, 15.665 to 15.696 for ²⁰⁷Pb/²⁰⁴Pb, and 39.981 to 39.081 for ²⁰⁸Pb/²⁰⁴Pb. Ultrapotassic shoshonites show the highest incompatible trace element contents coupled with the highest ⁸⁷Sr/⁸⁶Sr and the lowest ¹⁴³Nd/¹⁴⁴Nd. On the basis of geochemical and isotopic signatures it is argued that magmas were generated in a modified lithospheric peridotitic source containing metasomatic veins generated by K-rich melts from recycled sediments within the mantle via subduction. A further metasomatic event generated by slab-derived fluids pervasively enriched the peridotitic source. Partial melting of the veins produced leucite-free ultrapotassic magmas (i.e. lamproite), and was triggered by rising of the isotherms after the orogenic front migrated eastward in the Italian Peninsula. Further rise of the isotherms induced larger degrees of partial melting inducing melting of the surrounding wall peridotite. The variation of the degree of partial melting of such a heterogeneous peridotitic source produced a wide spectrum of magma compositions, which mimic a mixing line between two components: ultrapotassic magma from partial melting of the metasomatic vein and a basaltic andesitic magma from partial melting of the surrounding peridotite.  相似文献