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171.
Relative motion of the Adriatic with respect to the confining plates: seismological and geodetic constraints 总被引:3,自引:0,他引:3
172.
The correction, validation and homogenisation of the long temperature series of Padova (1725–1998) are discussed. After a careful historical investigation made in order to discover the metadata concerning the series, i.e., instrument features, calibrating methodologies, operational procedures (i.e., exposure, timing and number of daily observations), instrument maintenance, relocations and instrument replacements, the series has been corrected for all the systematic errors derived from any change in the instruments or the operative methodology. Above all, correction focused on instrumental drift, scale expansion, building influence, relationship between indoor-outdoor measurements, minima and maxima evaluation from observations performed at different times, homogenisation for difference of level and change of site. Statistical tests applied to the data and the comparison with other known series has clarified some uncertainties about exposure and operational procedures that the historical analysis of metadata was unable to solve. Moreover, gaps have been filled after the comparison of the series with others of neighbouring sites. The critical work of debugging, correcting, validating and homogenising the series is essential for a correct interpretation of data, as in some cases the errors that have been corrected have been found to be greater than the climate signal. Especially in the early period, the algebraic sum of the corrections of the mean daily temperature exceeds 8 ° C, where monthly corrections can reach 6 ° C. After correction, validation and homogenisation, the linear trend of the Padova series is positive, +0.31 ° C/100 yr over the period1774–today. Looking at post-industrial warming, the temperature rise is+0.44 ° C in the last 130 years, which means +0.34 ° C/100 yr, not farfrom the above bulk average. 相似文献
173.
Documentary Evidence on Climate in Sixteenth-Century Europe 总被引:2,自引:0,他引:2
174.
175.
Jean-Paul Toutain Jean-Claude Baubron Joseph Le Bronec Patrick Allard Pierre Briole Bernard Marty Gerarda Miele Dario Tedesco Giuseppe Luongo 《Bulletin of Volcanology》1992,54(2):147-155
The increasing activity of Vulcano Island (Italy) since 1985 led to the initiation of continuous geochemical monitoring of the lateral soil gas emissions. On the basis both of their relative geochemical characteristics and of local considerations, three gaseous components were selected for monitoring, namely CO2, He and 222Rn. Monitoring has been performed by means of specific analysers. Gases extracted from a water well located at the foot of the active cone were selected for monitoring, on the basis of their geochemical and isotopic characters that indicate their genetic link with central high temperature fumarolic gases emitted at the crater. Very strong variations of gas composition can be observed within one day (from 1 to about 94% for CO2). Some variations display a daily character and can be correlated with that of atmospheric pressure. The three monitored gases are highly correlated, suggesting very high kinetics of gas transfer in the system. Because of these considerable variations of chemical composition, bulk concentrations obviously are not suitable for monitoring at Vulcano. However, the evolution with time of ratios such as 222Rn/CO2 and He/CO2 (the latter being corrected for atmospheric contamination) supplies numerical parameters that the expected to characterize the intensity of the degassing process. A new input of magmatic gases, that would lead to an increase in the 222Rn/CO2 and He/CO2 ratios, should therefore be detected by such a monitoring station. 相似文献
176.
177.
The presence of chemical contaminants in marine coastal waters is a major subject of concern since many molecules are potentially immunotoxic, even at low concentration. During the last decade, studies in sentinel species, such as the blue mussel, Mytilus edulis, or the Pacific oyster, Crassostrea gigas, have revealed that immunosuppressive responses can be related to xenobiotic exposure, in the laboratory and in the field. In the present study, European flat oysters were experimentally exposed to heavy metals, to investigate possible alterations of their immune function. Several hematological and functional parameters of hemocytes were measured by flow cytometry, a technique allowing rapid, sensitive, cell-by-cell measurements in large cell populations. Results reveal a depression of phagocytosis and several subcellular, physiological changes in oysters exposed to cadmium alone or to cadmium and copper, suggesting an overall alteration of the phagocytic function. 相似文献
178.
Terlizzi A Bevilacqua S Scuderi D Fiorentino D Guarnieri G Giangrande A Licciano M Felline S Fraschetti S 《Marine pollution bulletin》2008,56(7):1303-1309
The exploitation of fossil fuels in the Mediterranean Sea will likely lead to an increase in the number of offshore platforms, a recognized threat for marine biodiversity. To date, in this basin, few attempts have been made to assess the impact of offshore gas and oil platforms on the biodiversity of benthic assemblages. Here, we adopted a structured experimental design coupled with high taxonomic resolution to outline putative effects of gas platforms on soft-bottom macrofauna assemblages in the North Ionian Sea. The analysis was based on a total of 20,295 specimens of 405 taxa, almost entirely identified at species level. Multivariate and univariate analyses showed idiosyncratic patterns of assemblage change with increasing distance from the platforms. Potential reasons underlying such inconsistency are analyzed and the view that structured experimental monitoring is a crucial tool to quantify the extent and magnitude of potential threats and to provide sound baseline information on biodiversity patterns is supported. 相似文献
179.
Dario Dello Iacono Aldo Zollo Maurizio Vassallo Tiziana Vanorio Sebastien Judenherc 《Bulletin of Volcanology》2009,71(3):275-284
In September 2001, an extensive active-seismic investigation (Serapis experiment) was carried out in the Gulfs of Naples and
Pozzuoli, with the aim of investigating and reconstructing the shallow crustal structure of the Campi Flegrei caldera, and
possibly identifying its feeding system at depth. The present study provides a joint analysis of the very shallow seismic
reflection data and tomographic images based on the Serapis dataset. This is achieved by reflection seismic sections obtained
by the 3D data gathering and through refined P-velocity images of the shallowest layer of Pozzuoli Gulf (z < 1,000 m). From the refined Vp model, the overall picture of the velocity distribution confirms the presence of a complex
arc-shaped anomaly that borders the bay offshore. The deeper part of the anomaly (beneath 700 m, with Vp > 3,500 m/s) correlates
with units made up of agglomerate tuffs and interbedded lava, which form the southern edge of the caldera, which was probably
formed following the two large ignimbritic eruptions that marked the evolutionary history of the area under study. The upper
part of the anomaly that tends to split into two parallel arcs is correlated with dikes, volcanic mounds and hydrothermal
alteration zones noted in previous shallow reflection seismic analyses. The depth of the transition between the upper and
lower parts of the anomaly is characterized by an abrupt Vp increase on the one-dimensional (1D) profiles extracted from the
3D tomographic model and by the presence of a strong reflector located at about 0.6/0.7 s Two Way Time (TWT) on Common Mid
Point gathers. The move-out velocity analysis and stack of the P–P and P–S reflections at the layer bottom allowed to estimate
relatively high Vp/Vs values (3.7 ± 0.9). This hypothesis has been tested by a theoretical rock physical modeling of the Vp/Vs
ratio as a function of porosity suggesting that the shallow layer is likely formed by incoherent, water saturated, volcanic
and marine sediments that filled Pozzuoli Bay during the post-caldera activity. 相似文献
180.
Dario Camuffo Caterina Secco Peter Brimblecombe Javier Martin-Vide 《Climatic change》2000,46(1-2):209-223
Data regarding the frequency andoccurrence of sea storms in the Adriatic Sea and theWestern Mediterranean during the last millennium havebeen extracted from historical written sources. TheAdriatic Sea shows two anomalous periods of high stormfrequency: the first half of the 1500s and the secondhalf of the 1700s. In the 1500s the storms were morefrequent in autumn, while in the late 1700s theyoccurred at high frequency in winter. In the WesternMediterranean, storms had a higher frequency in thefirst half of the 1600s, with two lesser periods ofhigh frequency in the 1400s and at the end of the1700s. Although both records show a maximum frequencyof sea storms during the Spörer Minimum(1416–1534) of solar activity, sunspot series yieldno, or poor, correlation during the other periods oflowest activity, i.e., Oort Minimum (1010–1090), WolfMinimum (1282–1342), and Maunder Minimum (1645–1715),suggesting that a teleconnection between sea stormsand sunspots is improbable or masked in this region.No teleconnection was found either between the ElNiño-Southern Oscillation (ENSO) and surgesflooding Venice or the Western Mediterranean storms orbetween Venice surges and the Northern AtlanticOscillation (NAO). 相似文献