Defining ecological and chemical reference conditions and restoration targets for nine European lakes     

Helen Bennion  Gavin L. Simpson  N. John Anderson  Gina Clarke  Xuhui Dong  Anders Hob?k  Piero Guilizzoni  Aldo Marchetto  Carl D. Sayer  Hansj?rg Thies  Monica Tolotti 《Journal of Paleolimnology》2011,45(4):415-431

This paper aims to determine the ecological and chemical reference conditions (~1800?C1850 AD) and degree of floristic change at nine enriched lakes, covering a range of types across Europe, using fossil diatom assemblages in dated sediment cores and application of total phosphorus (TP) transfer functions. Additionally the study assesses the potential of analogue matching as a technique for identifying reference sites and for estimating reference TP concentrations for the study lakes using a training set of 347 European lakes and 719 diatom taxa. Oligotrophic, acidophilous to circumneutral taxa were predominant in the reference samples of several of the deep lakes, and benthic Fragilaria spp. dominated the reference samples of two high alkalinity shallow lakes. The degree of floristic change from the reference sample, assessed using the squared chord distance (SCD) dissimilarity coefficient, revealed that two sites had experienced slight change (Lago Maggiore, Felbrigg Lake), five experienced moderate change (Mjoesa, Loch Davan, Loch Leven, White Lough, Esthwaite Water), and two showed evidence of major change (Groby Pool, Piburger See). For three lakes, there were no analogues in the diatom dataset owing to the uniqueness and diversity of the diatom reference assemblages. For the remaining six sites the number of analogues ranged from 2 to 44. For two deep lakes most of the analogues seemed appropriate as they were of the same type and had low TP concentrations. However, for two other deep lakes and two shallow lakes some of the analogues differed markedly in their depth and alkalinity from the lake in question or had TP concentrations seemingly too high to represent reference conditions suggesting that the analogues may not be suitable as reference sites. For the deep lakes, similar reference TP values were calculated using the EDDI Combined TP transfer function and the analogue matching technique with concentrations typically <20 ??g L^?1. However, for the shallow lakes, the analogue matching method produced inferred values considerably higher than those of the transfer function. The wide ecological tolerances of many of the diatom taxa found in the reference samples most likely explain the selection of inappropriate analogue sites. In summary, the study demonstrates that palaeoecological techniques can play a valuable role in determining reference conditions and indicates that the analogue matching technique has the potential to be a useful tool for identifying appropriate reference sites for lakes impacted by eutrophication.  相似文献   

Pollution effects of the Tuy River on the central Venezuelan coast: Anthropogenic organic compounds and heavy metals in Tivela mactroidea     

Rudolf Jaffe  Ivan Leal  Jose Alvarado  Piero Gardinali  Jos Sericano 《Marine pollution bulletin》1995,30(12):820-825

Bivalve samples were collected at seven sampling stations located between the town of Machurucuto and the Bay of Higuerote, Venezuela, covering approximately 70 km of coastline. Samples were collected both east and west of the Tuy River mouth, which has a plume known to move in a north-westerly direction. Petroleum hydrocarbons, both aliphatic (n-alkanes and UCM) and polyaromatic (PAHs), were detected and quantified in the samples. These hydrocarbons were found to be primarily derived from fossil fuels. Halogenated organics consisted mostly of polychlorinated biphenyls (PCBs) and some chlorinated pesticides, primarily of the DDT group. Heavy metals such as Pb, Cu, Ni, Zn, Cr and Cd were analysed in the samples. The results clearly show the influence of the Tuy River plume on the water quality of the coastal zone, particularly that located west of the river mouth. One sampling station, located just east of the river mouth, also showed significant influence from the river plume.  相似文献   

AN ION PROBE CONTRIBUTION TO RARE EARTH ELEMENT INVESTIGATION OF GABBRO GOG-1 USING SECONDARY ION MASS SPECTROMETRY   总被引：1，自引：0，他引：1  

Luisa OTTOLINI  Piero BOTTAZZI  Riccardo VANNUCCI  Massimo ODDONE 《Geostandards and Geoanalytical Research》1992,16(1):13-19

An updated REE measurement of Gabbro GOG-1 was carried out by means of secondary ion mass spectrometry (SIMS). The availability of high amount of rock powder allowed the sample to be well ground and homogenized before analysis. Fused glass pellets were employed for SIMS investigations. REE data were compared with new ICP-AES and NAA analyses. REE results from all employed analytical techniques show good agreement and are consistent with in-situ SIMS measurements of REE in major mineral phases forming GOG-1. Extensive homogeneity tests seem to confirm the possibility to using this rock as a reference material for earth sciences.  相似文献   

Reply to the Discussion by Maravelis and Zelilidis on “Unravelling provenance from Eocene–Oligocene sandstones of the Thrace Basin,North‐east Greece” by Caracciolo et al. (2011), Sedimentology, 58, 1988–2011.     

Luca Caracciolo  Salvatore Critelli  Fabrizio Innocenti  Niko Kolios  Piero Manetti 《Sedimentology》2013,60(3):865-869

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Environmental change in subtropical South America for the last two millennia as shown by lacustrine pigments     

Lisa Coianiz  Daniel Ariztegui  Eduardo L. Piovano  Andrea Lami  Piero Guilizzoni  Stefano Gerli  Nicolas Waldmann 《Journal of Paleolimnology》2015,53(2):233-250

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Magma-induced strain localization in centrifuge models of transfer zones   总被引：1，自引：0，他引：1  

Giacomo Corti  Marco Bonini  Francesco Mazzarini  Mario Boccaletti  Fabrizio Innocenti  Piero Manetti  Genene Mulugeta  Dimitrios Sokoutis 《Tectonophysics》2002,348(4)

Scaled centrifuge experiments have been used to investigate the dynamic relations between deformation and magma distribution in rift-related transfer zones. The physical models were built using suitable analogue materials, such as sand to represent the brittle upper crust, various kinds of silicone mixtures to simulate the lower crust and upper mantle and glycerol to reproduce magma. Models simulated the development of transfer zones across pre-existing glycerol reservoirs placed at the base of the analogue continental crust. In plan view, different geometries, dimensions and positions of subcrustal reservoirs were reproduced in three different sets of experiments; to compare results, models were also performed without magma-simulating glycerol.Set 1 experiments, incorporating a narrow rectangular glycerol reservoir, show that the low-viscosity material is able to localise deformation into the overlying crust, giving rise to discrete transfer zones. This concentrated surface deformation corresponds at depth to major magma accumulation. Set 2 experiments, with an initial wide squared glycerol reservoir, show instead that deformation is distributed across the whole model surface, corresponding at depth to relatively minor magma accumulation. Set 3 experiments explored various positions of a small squared reservoir that invariably localised faulting in the overlying analogue brittle crust at the onset of model deformation.The overall model behaviour suggests that magma distribution at depth can effectively control the strain distribution in the overlying crust and the deformative pattern of transfer zones. Strain distribution, in turn, may control magma emplacement as localized deformation would favour major accumulation of magma at transfer zones. Coupled to a strong thermal weakening of the country rocks, this process may ultimately lead to a positive feedback interaction between magma and deformation.  相似文献   

A deficit of faint red galaxies in the possible large-scale structures around the RDCS J1252.9−2927 cluster at z= 1.24     

Masayuki Tanaka  Tadayuki Kodama  Masaru Kajisawa  Richard Bower  Ricardo Demarco  Alexis Finoguenov  Chris Lidman  Piero Rosati 《Monthly notices of the Royal Astronomical Society》2007,377(3):1206-1214

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Earthquake early warning feasibility in the Campania region (southern Italy) and demonstration system for public school buildings     

Antonio Emolo  Matteo Picozzi  Gaetano Festa  Claudio Martino  Simona Colombelli  Alessandro Caruso  Luca Elia  Aldo Zollo  Piero Brondi  Nicola Miranda 《Bulletin of Earthquake Engineering》2016,14(9):2513-2529

We present the results of a feasibility study of an earthquake early warning system (EEWS) for the Campania region (southern Italy) using schools as specific targets. The study considered the seismogenic zones as sources of potential earthquakes for the area, the Italian accelerometric network as the recording network for seismic event occurrence, and the performances of the software platform PRESTo ^Plus for data analysis and processing. We analyze the distribution of lead-times for all possible threatening seismic sources for each municipality in the region under study by extracting the lead-time value corresponding to the 5th, 10th and 25th percentiles of the distributions. We discuss the results for the 5th percentile in order to analyze the worst-case scenario: in the case of a single site, the lead-time is expected to be larger than this value in the 95 % of the cases. Since the population distribution in Campania is uneven and most of the people live nearby the coast, whilst the most destructive earthquakes occur along the Apennine chain, we can conclude that an efficient EEWS can allow most of the schools in the area to undertake some mitigating actions. The testing of the EEWS was carried out in the high school ITIS ‘E. Majorana’, located at Somma Vesuviana, about 80 km from the seismogenic Irpinia region. For this purpose, the Sentinel, an actuator made up of low-cost hardware (i.e., Arduino^®), was developed in close cooperation with students and teachers of the school to receive alert messages from the PRESTo ^Plus platform and warn the school users in case of a seismic event. The EEWS and the Sentinel were successfully tested during some blind drills performed during normal school activities.  相似文献   

Evaluation of lindane diffusion along the southeastern Adriatic coastal strip (Mediterranean Sea): a case study in an Albanian industrial area     

Marini M  Betti M  Grati F  Marconi V  Mastrogiacomo AR  Polidori P  Sanxhaku M 《Marine pollution bulletin》2012,64(3):472-478

This study aimed to analyze the impact at sea of a pesticide factory located 7 km north of Durres (Albania) by investigating a lowland area under the sea situated 0.7 km from the shoreline. The main product of this factory was lindane. Production ceased in 1991 during the Albanian civil war, and a large amount of industrial waste was dispersed over the ground surrounding the factory, resulting in a high level of lindane pollution. A water-scoop channels the ground water accumulated around the disused factory directly into the sea. The concentrations of lindane in sediments collected along the coasts of the region ranged from 0.60 to 22.55 ng g(-1). The average concentration in the muscles of fish did not exceed the limits specified by European Commission legislation, whereas the concentration in the liver did exceed these limits; consequently, liver is not recommended for consumption.  相似文献   

Drill‐bit seismic interferometry with and without pilot signals*     

Flavio Poletto  Piero Corubolo  Paolo Comelli 《Geophysical Prospecting》2010,58(2):257-265

We use different interferometry approaches to process the seismic signals generated by a drill‐bit source in one well and recorded by seismic receivers located both in a second borehole and at the surface near the source well. We compare the standard interferometry results, obtained by using the raw drill‐bit data without a pilot signal, with the new interferometry results obtained by using the drill‐bit seismograms correlated with a reference pilot signal. The analysis of the stationary phase shows that the final results have different S/N levels and are affected by the coherent noise in the form of rig arrivals. The interferometry methods are compared by using different deconvolution approaches. The analysis shows that the results agree with the conventional drill‐bit seismograms and that using the reference pilot signal improves the quality of the drill‐bit wavefields redatumed by the interferometry method.  相似文献