Sonic tracking of wild cod, Gadus morhua, in an inshore region of the Bay of Fundy: a contribution to understanding the impact of cod farming for wild cod and endangered salmon populations     

Brooking  Paul; Doucette  Gino; Tinker  Steve; Whoriskey  Frederick G. 《ICES Journal of Marine Science》2006,63(7):1364-1371

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Airborne laser altimetry survey of Glaciar Tyndall, Patagonia   总被引：1，自引：1，他引：0  

Kristian Keller  Gino Casassa  Andrs Rivera  Rene Forsberg  Niels Gundestrup 《Global and Planetary Change》2007,59(1-4):101

The first airborne laser altimetry measurements of a glacier in South America are presented. Data were collected in November of 2001 over Glaciar Tyndall, Torres del Paine National Park, Chilean Patagonia, onboard a Twin Otter airplane of the Chilean Air Force. A laser scanner with a rotating polygon-mirror system together with an Inertial Navigation System (INS) were fixed to the floor of the aircraft, and used in combination with two dual-frequency GPS receivers. Together, the laser–INS–GPS system had a nominal accuracy of 30 cm after data processing. On November 23rd, a total of 235 km were flown over the ablation area of Glaciar Tyndall, with 5 longitudinal tracks with a mean swath width of 300 m, which results in a point spacing of approximately 2 m both along and across track. A digital elevation model (DEM) generated using the laser altimetry data was compared with a DEM produced from a 1975 map (1:50,000 scale — Instituto Geográfico Militar (IGM), Chile). A mean thinning of − 3.1 ± 1.0 m a^− 1 was calculated for the ablation area of Glaciar Tyndall, with a maximum value of − 7.7 ± 1.0 m a^− 1 at the calving front at 50 m a.s.l. and minimum values of between − 1.0 and − 2.0 ± 1.0 m a^− 1 at altitudes close to the equilibrium line altitude (900 m a.s.l.). The thinning rates derived from the airborne survey were similar to the results obtained by means of ground survey carried out at  600 m of altitude on Glaciar Tyndall between 1975 and 2002, yielding a mean thinning of − 3.2 m a^− 1 [Raymond, C., Neumann, T.A., Rignot, E., Echelmeyer, K.A., Rivera, A., Casassa, G., 2005. Retreat of Tyndall Glacier, Patagonia, over the last half century. Journal of Glaciology 173 (51), 239–247.]. A good agreement was also found between ice elevation changes measured with laser data and previous results obtained with Shuttle Radar Topography Mission (SRTM) data. We conclude that airborne laser altimetry is an effective means for accurately detecting glacier elevation changes in Patagonia, where an ice thinning acceleration trend has been observed during recent years, presumably in response to warming and possibly also drier conditions.  相似文献   

Potential use of microbial community investigations to analyse hydrothermal systems behaviour: the case of Ischia Island,Southern Italy     

Antonio Bucci  Gino Naclerio  Vincenzo Allocca  Pietro Celico  Fulvio Celico 《水文研究》2011,25(12):1866-1873

The Ischia hydrothermal system was analysed through hydrogeological and microbial community investigations. Mesophilic communities were detected in two cold springs, suggesting a negligible influence of thermal circuits in freshwater sub‐systems which are mainly or only fed by local precipitations. Thermophilic and extremely thermophilic bacteria were detected in two wells, according to higher water temperatures (61 and 85 °C), even if the two communities show significant differences. In one well, thermophilic and extremely thermophilic bacteria are associated with strains belonging to ε‐Proteobacteria isolated in different sulphur‐rich carbonate environments. This association suggests a greater influence on ascending hot fluids that interact with the carbonate basement of volcanic rocks. In the other well, thermophilic and extremely thermophilic bacteria are associated with strains isolated in cold hypersaline environments or in aquatic habitats where terrestrial and marine components are coupled. This association supports the fact that seawater intrusion can affect this part of Ischia, according to results of hydrogeological and geochemical surveys. Differences in groundwater temperature and bacterial communities are probably mainly due to differences in permeability between volcanic rocks and differences in hydrogeologic behaviour between faults in the upper carbonate basement, above the deep magma chamber, that influence relationships between ascending hot fluids and local recharge. This study contributes to discussion of the reliability of the actual behaviour models of the Ischia system, based on the results of geochemical and isotopic investigations, and, in a wider context, it shows that microbial community investigations may be a valuable supplementary tool for analysing hydrothermal system behaviour. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

An Evaluation of the Reproducibility of Forced-Gradient Solute Transport Tests     

Gino C. Bianchi-Mosquera  Douglas M. Mackay 《Ground water》1994,32(6):937-948

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Gino Cecchini 《Journal of Geodesy》1954,28(1):9-10

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Geochemical and geochronological data on Triassic volcanism of the Southern Alps of Lombardy (Italy): Genetic implications     

C. M. Crisci  G. Ferrara  R. Mazzuoli  P. M. Rossi 《International Journal of Earth Sciences》1984,73(1):279-292

Summary A widespread volcanism mainly consisting of pyroclastic products and lava flows is found in the Southern Alps of Lombardy. The volcanics are interbedded with Anisian-Ladinian carbonatic sequences and continental terrigenous or transitional deposits of Ladinian-Carnian age. The petrographic and geochemical data for this volcanism indicate a calc-alkaline affinity with characters similar to those of convergent continental margins. In this sector of the Alps the geological evidences show that in the middle Triassic general extensional movements were the dominant deformation event, and do not support the existence of a subduction zone during this period. The apparent contrast between the tectonic environment and the type of magmas erupted in the Anisian-Carnian is tentatively explained by partial melting during the early stage of rifting of an upper mantle deeply modified during the previous Hercynian orogenesis and contaminated by crustal material. This hypothesis is in agreement with the preliminary Sr isotopic ratios (0.705 and 0.709). K/Ar and Rb/Sr ages on biotites date the beginning of the volcanism at around 225 m.y.

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Zusammenfassung In den Südalpen der Lombardei befindet sich ein weitverbreiteter Vulkanismus, der hauptsächlich aus pyroklastischen Produkten und Lavaströmen besteht. Vulkanische Produkte sind mit anisisch-ladinischen beckenartigen Karbonat-Schichtfolgen oder mit ladinisch-karnischen kontinental-terrestrischen oder Übergangsablagerungen eingebettet. Die petrographischen und geochemischen Daten für diesen Vulkanismus weisen auf eine den konvergenten Kontinentalschelfen ähnliche kalkalkaline Affinität hin. In diesem Sektor der Alpen zeigen die geologischen Beobachtungen, daß die dominanten Verformungsereignisse der mittleren Trias allgemeine Dehnungsbewegungen waren und weisen nicht auf die Existenz einer Subduktionszone zu dieser Zeit hin. Der scheinbare Widerspruch zwischen dem tektonischen Milieu und dem im Anis bis Karn ausgeworfenen Magmatyp wird versuchsweise mit einer Teilaufschmelzung eines während der vorhergehenden herzynischen Orogenese tief veränderten und mit Krustenmaterial verunreinigten oberen Mantels während der Frühphase einer Grabenbildung erklärt. Diese Hypothese ist im Einklang mit den präliminaren Sr-Isotopenverhältnissen (0.705 und 0.709). K/Ar und Rb/Sr Altersmessungen an Biotiten datieren den Anfang der vulkanischen Tätigkeit um 225 Ma.

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Résumé Un volcanisme très répandu constitué surtout par des produits pyroclastiques et par des coulées de lave se trouve dans les Alpes Méridionales en Lombardie. Ces produits volcaniques sont intercalés dans la série carbonatique du bassin d'âge Anisien-Ladinien et dans les dépôts terrigènes continentaux ou transitionnels d'âge Ladinien-Carnien. Les données pétrographiques et géochimiques de ces produits volcaniques montrent une affinité calcoalcaline avec des caractères semblables à ceux des marges continentales convergentes. Dans le Trias moyen de cette partie des Alpes, les données géologiques indiquent que le motif dominant de la déformation est un mouvement d'extension très répandu, tandis qu'il n'y a aucune évidence de l'existence d'une zone de subduction durant cette période. Le contraste entre le style tectonique et le type de magma mis en place dans l'Anisien-Carnien, peut être expliqué par une fusion partielle du manteau supérieur pendant un stade précoce d'effondrement modifié intensément pendant la précédente orogenèse hercynienne et contaminé par des matériaux d'origine crustale. Cette hypothèse est en accord avec des données préliminaires des rapports isotopiques du Sr (0.705 et 0.709). Des âges K/Ar et Rb/Sr sur des biotites donnent 225 m.a. environ pour le début de l'activité volcanique.

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On the collapse of a gaseous isothermal sphere: An analytical solution     

Gino Ballone  Massimo Fofi 《Astrophysics and Space Science》1982,85(1-2):293-296

An analytical solution in terms of elliptic integrals is found for the problem connected to the isolthermal collapse of a gaseous sphere. In this way the time-dependence of spatial density distribution is promptly obtained in each point inside the sphere itself. An application for interstellar clouds is given.  相似文献   

Spectral mapping of the spiral structures in IP Pegasi on the decline from an outburst     

Raymundo Baptista  Carole A. Haswell  Gino Thomas 《Monthly notices of the Royal Astronomical Society》2002,334(1):198-208

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Optical Monitoring of bright Blazars with Automatic Telescopes     

Enrico Massaro  Roberto Nesci  Gino Tosti 《Astrophysics and Space Science》2002,282(1):141-147

Well sampled light curves of BL Lac objects are very useful to understand the physical processes responsible for the highly variable emission from this class of AGN. The best way to perform the necessary high number of observations is the use of automatic small aperture telescopes. We present some results of the Perugia-Roma monitoring program concerning the recent active phase of BL Lac and the Intra-Day Variability of S5 0716+714. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Theoretical analysis and simulation for avoiding antenna oscillations without distributed resistance     

Gonzalo Garcia  Jos A. Uribe  David Ulloa  Rodrigo Zamora  Gino Casassa 《Journal of Applied Geophysics》2009,67(4):374

The so-called Wu and King antenna pattern is widely used in GPR because of its simple design and construction features. The main disadvantage is its limited efficiency due to transmitter energy losses which occur through lumped resistors. Based on the analysis of the electromagnetic field behaviour across the antenna, it is possible to replace the effect of the resistors by either storing the energy of the electric pulses, or damp them by means of one matched resistor, which will theoretically improve the efficiency of the antenna. In this paper we provide a theoretical analysis using a modified transmission line model together with simulation based on delayed potentials among other electromagnetic software, and measurement results using an impulse transmitter with fast MOSFET switches and a matched resistor that support this idea.  相似文献