Localised strain in fissured clays: the combined effect of fissure orientation and confining pressure     

Tudisco  Erika  Vitone  Claudia  Mondello  Cristina  Viggiani  Gioacchino  Athanasopoulos  Stefanos  Hall  Stephen A.  Cotecchia  Federica 《Acta Geotechnica》2022,17(5):1585-1603

Acta Geotechnica - This paper reports the main results of an experimental study on the mechanics of intensely fissured natural clays, extending our previous studies on scaly clay from Santa Croce...  相似文献   

http://www.sciencedirect.com/science/article/pii/S1674987114000231     

Carlo Doglioni  Eugenio Carminati  Mattia Crespi  Marco Cuffaro  Mattia Penati  Federica Riguzzi 《地学前缘(英文版)》2015,6(3):401-418

The possibility of a net rotation of the lithosphere with respect to the mantle is generally overlooked since it depends on the adopted mantle reference frames,which are arbitrary.We review the geological and geophysical signatures of plate boundaries,and show that they are markedly asymmetric worldwide.Then we compare available reference frames of plate motions relative to the mantle and discuss which is at best able to fit global tectonic data.Different assumptions about the depths of hotspot sources(below or within the asthenosphere,which decouples the lithosphere from the deep mantle) predict different rates of net rotation of the lithosphere relative to the mantle.The widely used no-net-rotation(NNR) reference frame,and low(0.2°-0.4° /Ma) net rotation rates(deep hotspots source) predict an average net rotation in which some plates move eastward relative to the mantle(e.g.,Nazca).With fast(1° /Ma) net rotation(shallow hotspots source),all plates,albeit at different velocity,move westerly along a curved trajectory,with a tectonic equator tilted about 30° relative to the geographic equator.This is consistent with the observed global tectonic asymmetries.  相似文献   

Slope instability processes in intensely fissured clays: case histories in the Southern Apennines     

Federica Cotecchia  Claudia Vitone  Francesca Santaloia  Giuseppe Pedone  Osvaldo Bottiglieri 《Landslides》2015,12(5):877-893

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Viriobenthos in aquatic sediments: variability in abundance and production and impact on the C-cycle     

Federica Pinto  Stefano Larsen  Peter Casper 《Aquatic Sciences - Research Across Boundaries》2013,75(4):571-579

In the last 15 years viruses have been acknowledged as important components of the benthic microbial community, but our understanding of their role in the functioning of aquatic systems remains poor. Viruses can affect bacterial assemblages and mineralization activities, but the extent of their influence remains unclear. We synthesised available data on viriobenthos dynamics to understand which factors drive the variability in their abundance and production and to quantify their influence on the benthic carbon cycle. Results highlighted a large variability in viral abundance (from 2 × 10⁸ to 7 × 10⁹ virus ml^?1) and production estimates (from 1 × 10⁷ to 5 × 10⁸ virus ml^?1 h^?1) obtained with different techniques. This variability limits the comparability of data across studies and indicates the need to improve protocols and develop standard methods. The dynamics of viruses infecting prokaryotes appeared linked to prokaryotic metabolism, supporting the hypothesis that benthic viruses originate directly in the sediment as a result of infection events rather than sinking from the water column. Sediment characteristics (porosity, temperature, depth) appeared to effect viral production, mostly indirectly by influencing bacterial productivity and abundance, but possibly also interfering with the rate of virus–host encounter. Conversely, trophic status appeared unrelated to viral parameters. Viral contribution to carbon turnover appeared low and unrelated to temperature, water depth, trophic status and salinity. More detailed studies are needed to understand the pelagic contribution to the viriobenthos and the extent to which dissolved organic carbon released by viruses is effectively used by bacteria.  相似文献   

Improving the resilience of existing built assets to earthquake induced liquefaction disaster events     

Jones  Keith G.  Morga  Mariantonietta  Wanigarathna  Nadeeshani  Pascale  Federica  Meslem  Abdelghani 《Bulletin of Earthquake Engineering》2021,19(10):4145-4169

Bulletin of Earthquake Engineering - LIQUEFACT was a EU H2020 funded project to investigate earthquake induced liquefaction potential across Europe and develop a series of tools to understand...  相似文献   

Three-dimensional radial anisotropic structure of the North American upper mantle from inversion of surface waveform data   总被引：1，自引：0，他引：1  

Federica Marone  Yuancheng Gung  Barbara Romanowicz 《Geophysical Journal International》2007,171(1):206-222

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Variation in the Sizes of Chthamalid ­Barnacle Post-Settlement Cyprids on European Shores     

Ruth M. O'Riordan  Jane Delany    David McGrath    Alan A. Myers  Anne Marie Power    Neil F. Ramsay  Damaso Alvarez  Teresa Cruz  Federica G. Pannacciulli    Pedro Range  & Giulio Relini 《Marine Ecology》2001,22(4):307-322

Abstract. As part of a wider study on the settlement and recruitment of Chthamalus spp. in Europe, this study investigated whether chthamalid cyprids can be separated by length on a European scale. Variation in cyprid length with latitude and temporal variation at selected localities were also examined. The lengths of cyprids collected between 1996 – 1999 on nine rocky shores in Europe are reported. Elminius modestus cyprids were found only at Roscoff, NW France and could be distinguished due to their carapace shape and length. They showed a unimodal length distribution, measuring between 450 and 625 µm, with no variation in length between the two sampling dates (1997 and 1998). Based on carapace shape and length, the remaining cyprids in the collections were identified as one of three chthamalid species, Chthamalus montagui, Chthamalus stellatus or Euraphia depressa. Bimodal length distributions of chthamalid cyprids were seen on some shores, while others had a single small‐sized modal group (representing C. montagui on Atlantic shores and/or E. depressa in the Mediterranean) separated from a few distinctly larger cyprids (C. stellatus). Metamorphs collected simultaneously with cyprid collections were identified as C. stellatus or C. montagui, except at Roscoff, where E. modestus were also found. In southern Portugal, where all metamorphs collected were C. montagui and adult C. montagui were the dominant barnacles, most cyprids measured between 350 and 550 µm long and this size distribution coincides with the distribution expected for C. montagui. Cyprids collected on these four more southerly Portuguese shores had the same modal length class (475 µm) and this remained constant between successive years at Luz and Albufeira, Algarve. The smallest (350 µm long) wild chthamalid cyprids found were from southern Portugal and Italy. In Spain, France and Ireland the smallest chthamalid cyprid was 425 µm long. The results from the present study support the hypothesis that on Atlantic shores cyprids of C. montagui can be separated from those of C. stellatus based on size, although there is some variation in cyprid length with latitude as well as temporal variation at selected localities.  相似文献   

Calibration and validation of rockfall modelling at regional scale: application along a roadway in Mallorca (Spain) and organization of its management   总被引：1，自引：0，他引：1  

Rosa María Mateos  Inmaculada García-Moreno  Paola Reichenbach  Gerardo Herrera  Roberto Sarro  Joan Rius  Raúl Aguiló  Federica Fiorucci 《Landslides》2016,13(4):751-763

The Tramuntana range, in the northwestern sector of the island of Mallorca (Balearic Islands, Spain), is frequently affected by rockfalls which have caused significant damage, mainly along the road network. In this work, we present the procedure we have applied to calibrate and validate rockfall modelling in this region, using 103 cases of the available detailed rockfall inventory (630 rockfall events collected since the eighteenth century). We have exploited STONE (Guzzetti et al. 2002), a GIS-based rockfall simulation software which computes 2D and 3D rockfall trajectories starting from a DTM and maps of the dynamic rolling friction coefficient and of the normal and tangential energy restitution coefficients. The appropriate identification of these parameters determines the accuracy of the simulation. To calibrate them, we have selected 40 rockfalls along the range which include a wide variety of outcropping lithologies. Coefficients values have been changed in numerous attempts in order to select those where the extent and shape of the simulation matched the field mapping. Best results were summarized with the average statistical values for each parameter and for each geotechnical unit, determining that mode values represent more precisely the data. Initially, for the validation stage, 10 well-known rockfalls exploited in the calibration phase have been selected. Confidence tests have been applied to their modelling results taking into account not only the success but also the mistakes. The best accuracy is obtained when the rockfall has a preferential trajectory and worse results when the rockfall follows two or more trajectories. Additionally, the greater the rockfall runout length, the less precise the simulation is. We have further validated the calibrated parameters along the Ma-road (111 km), the main transportation corridor in the range, using 63 rockfall events that occurred during the past 18 years along the road. Of the rockfalls where source areas were properly identified, 81.5 % are well represented by STONE modelling, as the travel paths and the depositional areas are successfully ascertained. Results of the analysis have been used by the Road Maintenance Service of Mallorca to assess hazard and risk posed by rockfall at regional scale to design the road management plan.  相似文献   

The ground-based InSAR monitoring system at Stromboli volcano: linking changes in displacement rate and intensity of persistent volcanic activity   总被引：1，自引：1，他引：0  

Federico Di Traglia  Emanuele Intrieri  Teresa Nolesini  Federica Bardi  Chiara Del Ventisette  Federica Ferrigno  Sara Frangioni  William Frodella  Giovanni Gigli  Alessia Lotti  Carlo Tacconi Stefanelli  Luca Tanteri  Davide Leva  Nicola Casagli 《Bulletin of Volcanology》2014,76(2):1-18

Stromboli volcano (Aeolian Archipelago, Southern Italy) experienced an increase in its volcanic activity from late December 2012 to March 2013, when it produced several lava overflows, major Strombolian explosions, crater-wall collapses pyroclastic density currents and intense spatter activity. An analysis of the displacement of the NE portion of the summit crater terrace and the unstable NW flank of the volcano (Sciara del Fuoco depression) has been performed with a ground-based interferometric synthetic aperture radar (GBInSAR) by dividing the monitored part of the volcano into five sectors, three in the summit vents region and two in the Sciara del Fuoco. Changes in the displacement rate were observed in sectors 2 and 3. Field and thermal surveys revealed the presence of an alignment of fumaroles confirming the existence of an area of structural discontinuity between sectors 2 and 3. High displacement rates in sector 2 are interpreted to indicate the increase in the magmastatic pressure within the shallow plumbing systems, related to the rise of the magma level within the conduits, while increased displacement rates in sector 3 are connected to the lateral expansion of the shallow plumbing system. The increases and decreases in the displacement rate registered by the GBInSAR system in the upper part of the volcano have been used as a proxy for changes in the pressure conditions in the shallow plumbing system of Stromboli volcano and hence to forecast the occurrence of phases of higher-intensity volcanic activity.  相似文献   

Landslide distribution and size in response to Quaternary fault activity: the Peloritani Range,NE Sicily,Italy          下载免费PDF全文

Francesco Bucci  Michele Santangelo  Mauro Cardinali  Federica Fiorucci  Fausto Guzzetti 《地球表面变化过程与地形》2016,41(5):711-720

Landslides contribute to dismantle active mountain ranges and faults control the location of landslides. Yet, evidence of the long‐term, regional dependency of landslides on active faults is limited. Previous studies focused on the transient effects of earthquakes on slope stability in compressive and transcurrent regimes. Here we show that in the Peloritani range, NE Sicily, Italy, one of the fastest uplifting areas in the Mediterranean, a clear geographical association exists between large bedrock landslides and active normal faults of the Messina Straits graben. By interpreting aerial photographs, we mapped 1590 landslides and sackungs and 626 fault elements and their facets in a 300 km² area in the eastern part of the range. We used the new landslide and fault information, in combination with prior geological and seismic information, to investigate the association between bedrock landslides and faults. We find that the distribution and abundance of landslides is related to the presence of large active normal faults, and matches the pattern of the local historical seismicity. Landslide material is more abundant along the East Peloritani Fault System where the long‐term activity of the faults, measured by the average yearly geological moment rate, is larger than in the West Peloritani Fault System where landslides are less abundant. Along the fault systems landslide material concentrates where the cumulated fault throws are largest. We conclude that large landslides and their cumulated volume are sensitive to local rates of tectonic deformation, and discriminate the deformation of the single fault segments that dissect the Peloritani range. Our findings are a direct test of landscape evolution models that predict higher rates of landslide activity near active faults. Our work opens up the possibility of exploiting accurate landslide and fault maps, in combination with geological and seismic information, to characterize the long‐term seismic history of poorly instrumented active regions. © 2015 The Authors Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd  相似文献