Active tectonics of the Northern Apennines and Adria geodynamics: new data and a discussion     

Daniela Di Bucci  Stefano Mazzoli 《Journal of Geodynamics》2002,34(5):27

The active geodynamic setting of the Northern Apennines is characterised by extension in the axial zone of the chain, and by a more complex tectonic behaviour in the frontal part of the belt. In the latter sector, moderate seismicity occurs, displaying compressional, strike-slip and extensional focal plane solutions with variably oriented P and T axes. For this area, a review of available geological and geophysical data has been integrated by the analysis of seismic reflection lines calibrated with deep well logs. This study confirms that, as already suggested by some previous workers, thrusting and related folding in the study area ceased in Early Pleistocene times. This feature is in contrast with the hypothesis of active thrusting related to a subducting lithospheric slab beneath the chain—an issue which is largely debated based on available geophysical information. Our analysis shows that the Northern Apennines are characterised by an active tectonic setting which is similar to that of the central and southern portions of the belt. These areas all display a Late Quaternary inactivity of the thrust front. NE–SW oriented extension (perpendicular to the strike of the orogen) is well established in their axial zones, whereas a less homogeneous stress field characterises their external sectors and the adjacent foreland. Within this framework, the seismotectonic behaviour of the Northern Apennines—and probably of the whole Italian peninsula between the Po Plain and the Southern Apennines (north of the Calabrian Arc)—may be interpreted as essentially controlled by two main processes. The first of them involves tectonic uplift, possibly related with slab detachment and associated unbending of the foreland plate. The second process consists of a present-day northwestward motion of the Adria block with respect to stable Europe.  相似文献   

Hydrodynamic modelling of mesoscale eddies in the Black Sea     

Cecilia E. Enriquez  Georgy I. Shapiro  Alejandro J. Souza  Andrei G. Zatsepin 《Ocean Dynamics》2005,55(5-6):476-489

A three dimensional structure of mesoscale circulation in the Black Sea is simulated using the Proudman Oceanographic Laboratory Coastal Ocean Modelling System. A number of sensitivity tests reveal the response of the model to changes in the horizontal resolution, time steps, and diffusion coefficients. Three numerical grids are examined with x-fine (3.2 km), fine (6.7 km) and coarse (25 km) resolution. It is found that the coarse grid significantly overestimates the energy of the currents and is not adequate even for the study of basin-scale circulation. The x-fine grid, on the other hand, does not give significant advantages compared to the fine grid, and the latter is used for the bulk of simulations. The most adequate parameters are chosen from the sensitivity study and used to model both the basin-scale circulation and day-to-day variability of mesoscale currents for the months of May and June of 2000. The model is forced with actual wind data every 6 h and monthly climatic data for evaporation, precipitation, heat fluxes and river run-off. The results of the fine grid model are compared favourably against the satellite imagery. The model adequately reproduces the general circulation and many mesoscale features including cyclonic and anticyclonic eddies, jets and filaments in different parts of the Black Sea. The model gives a realistic geographical distribution and parameters of mesoscale currents, such as size, shape and evolution of the eddies.  相似文献   

Institutional change and natural resource use in coastal Vietnam   总被引：1，自引：0，他引：1  

Cecilia Luttrell 《GeoJournal》2001,55(2-4):529-540

Vietnam is currently undergoing a rapid economic and social transition involving the dismantling of the co-operative system and the official embracing of a market economy. The paper uses an institutional approach to examine adaptation to such changes in two coastal communes in mangrove forest areas. Having provided the historical and policy context of reforms which have taken place in Vietnam in the area of resource management, the paper goes on to discuss changes currently taking place in access to resources. The complexity of property rights regimes are then examined in the light of such changes, with particular focus on the effects of privatisation and the increased effects of integration with external markets. Using livelihood diversification as a key concept for understanding local adaptation to such changes, the paper concludes with discussion of the socially differentiated impacts of the process and the implications for future livelihoods. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Speckle filtering of Synthetic Aperture Radar images using filters with object-size-adapted windows     

Sahel Mahdavi  Bahram Salehi  Cecilia Moloney  Weimin Huang  Brian Brisco 《International Journal of Digital Earth》2018,11(7):703-729

Speckle degrades the radiometric quality of a Synthetic Aperture Radar (SAR) image. Previous methods for speckle reduction have used a fixed-size window for filtering the entire image. This, however, may not be effective for the entire image, as land covers of different sizes require different filtering windows. In this paper, a novel method is proposed by which each pixel in the image is filtered with a window appropriate for the size of object within it. The real in-phase and the imaginary quadrature components of the SAR images determine the best window size and the pixels in the intensity image are filtered using their own optimal windows. The proposed method is presented for both single- and multi-polarized SAR images, and the results of several common filters that were modified are presented. This approach is applied to two RADARSAT-2 images: one over San Francisco, California, USA and the other over St. John’s, Newfoundland and Labrador, Canada, producing results that were similar to, or outperformed, comparable filters while retaining details and suppressing speckle effectively. While the method was successful for single-look intensity data, it offers great potential for multi-look and amplitude data as well.  相似文献   

Characterizing proteases in an Antarctic Janthinobacterium sp. isolate：Evidence of a protease horizontal gene transfer event     

Cecilia Martinez-Rosales  Juan Jos Marizcurrena  Andrs Iriarte  Natalia Fullana  Hctor Musto  Susana Castro-Sowinski 《极地研究(英文版)》2015,(1)

We report the isolation of a cold-adapted bacterium belonging to the genus Janthinobacterium (named AU11), from a water sample collected in Lake Uruguay (King George Island, South Shetlands). AU11 (gro...  相似文献   

Defining the acceptable level of risk for civil protection purposes: a behavioral perspective on the decision process     

Daniela Di Bucci  Lucia Savadori 《Natural Hazards》2018,90(1):293-324

This work analyzes how acceptable risk levels are determined in political decisions and related policies in the field of civil protection, i.e., regarding disaster risks and their reduction at the national and supranational level. We examined why establishing the acceptable level of risk is a political decision, and why this decision is not an easy task. Some behavioral elements which can de facto impede such a decision were recognized. Among these, the anomalies inherent in intertemporal choices, availability heuristic and mental accounting play a primary role, because they interfere with preferences for selfish versus others’ interests and with the evaluation of individual versus community gains and losses. Due to these processes, the political decision-maker, unless she is a statesperson, will easily prefer not to decide. Political decision-making, however, could be induced by a change of mind in the voters’ community. This reorientation of the society’s values and interests can be stimulated taking advance from research on social norms, which underlines the role played by some people that drive innovation in a community, e.g., the trendsetters. The scientific, technical and professional communities have the knowledge needed, are aware of the work to be done on the disaster risk reduction and can establish a direct relationship with single trendsetters and statespersons to promote decision-making on disaster risk reduction. Within this relationship, they can build trust, give advice and participate in in-depth discussions. In this interaction and collaboration, behavioral sciences can provide a valuable support for a better reciprocal understanding.  相似文献   

Macrobenthic surf zone communities of temperate sandy beaches: spatial and temporal patterns          下载免费PDF全文

Cecilia Carcedo  Sandra Fiori  Claudia Bremec 《Marine Ecology》2015,36(3):326-336

The spatial and temporal patterns within the surf zone epibenthic assemblages were studied in a coastal fringe of Argentina to determine whether assemblage compositions, abundance, species richness and diversity vary spatially and temporarily. Sampling was conducted seasonally in two sandy beaches over 2 years with a benthic sledge used to collect the fauna in the upper centimeters of soft bottom sediments and the epifauna on the sediment surface. Physical variables were measured in the same coastal sites where biological sampling was conducted. A total of 58 morphospecies were collected. Peracarid crustaceans were the most abundant group. The mysid Pseudobranchiomysis arenae (new genus–new species) (29.73 ± 17.79 ind. per sample) and the isopod Leptoserolis bonaerensis (51.54 ± 22.35 ind. per sample) were the most abundant and common species and were present regularly throughout the sampling period. Differences in the surf zone community composition were found between the beaches; these differences could be related to variation in physical parameters such as sand grain size and wave climate, indicating the possible influence of the morphodynamic state of the beaches on the epibenthic assemblages. A seasonal abundance trend was detected, reflecting the changes in abundance of the two dominant species; the richness pattern was not easily detectable due to the sporadic appearance of non‐resident species in the surf zone, probably due to different causes, including dispersion by entry of water from surrounding areas, littoral currents and storms. The surf zone studied presents a complex and dynamic epibenthic community that appears to be influenced by the morphodynamic state of the beach and the dynamic of non‐resident species.  相似文献   

A multivariate assessment of coastal eutrophication. Examples from the Gulf of Finland, northern Baltic Sea   总被引：1，自引：0，他引：1  

Lundberg C  Lönnroth M  von Numers M  Bonsdorff E 《Marine pollution bulletin》2005,50(11):1185-1196

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Reconstructing recent environmental changes using non-biting midges (Diptera: Chironomidae) in two high mountain lakes from northern Patagonia,Argentina     

Fernanda Montes de Oca  Luciana Motta  María Sofía Plastani  Cecilia Laprida  Andrea Lami  Julieta Massaferro 《Journal of Paleolimnology》2018,59(2):175-187

Remote lakes of northern Patagonia are ideal sites for examining climate- and non-climate-driven changes in aquatic ecosystems because there is little evidence of human influence and there is no detailed information on recent environmental trends in the region (i.e. the last 200 years). Subfossil chironomids (Diptera: Chironomidae) are useful paleoindicators due to their specific response to numerous environmental factors. Here, we analyze the chironomid subfossil assemblages from two remote lakes located in different environmental settings in Nahuel Huapi National Park of northern Patagonia, Argentina. Chironomids combined with sedimentary pigments (chlorophyll derivatives and total carotenoids) and organic matter provided information on the environmental history of the lakes for the last ca. 200 years. The ²¹⁰Pb chronology and tephra layers are used to establish the chronology of changes in the chironomid assemblages associated to different environmental factors that impacted the area during the period covered by the study. The deposition of volcanic ash affected the abundance and composition of chironomid assemblage throughout the record of both lakes. However, changing climate conditions and human activities are also responsible for chironomid changes in the last 50 years.  相似文献   

Photostability and photolability of dissolved organic matter upon irradiation of natural water samples under simulated sunlight   总被引：2，自引：0，他引：2  

Davide Vione  Vittorio Lauri  Claudio Minero  Valter Maurino  Mery Malandrino  Maria Eugenia Carlotti  Romeo-Iulian Olariu  Cecilia Arsene 《Aquatic Sciences - Research Across Boundaries》2009,71(1):34-45

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