First evidence of post-seismic deformation in the central Mediterranean: Crustal viscoelastic relaxation in the area of the 1980 Irpinia earthquake (Southern Italy)     

G. Dalla Via  G. De Natale  C. Troise  F. Pingue  F. Obrizzo  R. Riva  R. Sabadini 《Geophysical Journal International》2003,154(3):F9-F14

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Barred galaxy resonance rings: analytically explaining morphology and predicting dissipative misalignment     

Gene G. Byrd  Derrick Ousley  & Chris Dalla Piazza 《Monthly notices of the Royal Astronomical Society》1998,298(1):78-86

Many barred disc galaxies show rings of gas clouds and young stars thought to be in periodic orbits near the two-fold inner and outer Lindblad resonances (ILR and OLR) plus a four-fold ultraharmonic resonance (UHR) of the turning bar with oscillations about the disc orbital motion. To confirm and extend simulations by Schwarz and by Byrd et al. of resonance ring formation, we present an analytical formulation of the clouds' orbital motion which includes dissipative damping of oscillations relative to the local interstellar medium plus the rotation curve, bar pattern speed, and strength. Observed ring morphology matches our plots of periodic orbits where the density is enhanced but clouds do not collide violently. Pairs of 'outer rings' bracket the OLR. Dimpled outer rings like that of ESO 507-16 can be matched by plots with strong bars. Slightly dimpled outer rings like that of ESO 509-98 can be matched by weak bar plots. For flat rotation curves, a pair of two-fold rings bracket the ILR; the smaller can be identified with the tiny 'nuclear rings'. We find narrow UHR rings just outside this pair as well as just inside the OLR pair. We confirm the identification of the larger ILR ring and the inner UHR ring with 'inner rings'. Disagreeing with the common identification, we associate the dimpled outer rings with the UHR just inside the OLR. See ESO 507-16 as an example. We predict that damping can misalign the ILR and OLR rings relative to the bar as seen in our match to ESO 507-16. We find that for weak bars, if the linearly rising portion of the rotation curve is a significant fraction of the corotation radius, nuclear and inner rings are absent with outer rings still present. We show this in a match to ESO 509-98. Success of the matches to ESO 507-16 and 509-98 shows how the analytic formulation can be used to estimate disc orientation and pattern speed if rotation curve observations are available.  相似文献   

Detecting geophysical signals in gravity satellite missions     

F. Migliaccio  M. Reguzzoni  F. Sansò  G. Dalla Via  R. Sabadini 《Geophysical Journal International》2008,172(1):56-66

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Hillslope scale soil moisture variability in a steep alpine terrain   总被引：1，自引：0，他引：1  

Daniele Penna  Marco Borga  Daniele Norbiato  Giancarlo Dalla Fontana 《Journal of Hydrology》2009,364(3-4):311-327

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Vibrios in association with sedimentary crustaceans in three beaches of the northern Adriatic Sea (Italy)   总被引：3，自引：0，他引：3  

Covazzi Harriague A  Brino MD  Zampini M  Albertelli G  Pruzzo C  Misic C 《Marine pollution bulletin》2008,56(3):574-579

In the marine environment, vibrios adhere to a number of substrates including chitin-rich organisms such as crustaceans. Their wide diffusion in coastal waters and pathogenic potential require knowledge of the lifestyle and environmental reservoirs of these bacteria. To test the presence of culturable vibrios in coastal areas and their association with benthic crustaceans, vibrios were isolated from water, sediments and crustaceans (copepods and anphipods) at three stations placed in front of heavily used tourist beaches of the Adriatic Sea. We observed significant correlations between vibrios and temperature. Benthic and planktonic copepods harboured vibrios in summer, while benthic amphipods harboured these bacteria in spring and autumn. Vibrio alginolyticus and Vibrio parahaemolyticus strains gave positive results using primers for Vibrio cholerae toxR and toxS. Sedimentary crustaceans may extend Vibrio persistence in seawater and may represent an additional aquatic reservoir of these bacteria.  相似文献   

Eruption of kimberlite magmas: physical volcanology, geomorphology and age of the youngest kimberlitic volcanoes known on earth (the Upper Pleistocene/Holocene Igwisi Hills volcanoes, Tanzania)     

Richard J. Brown  S. Manya  I. Buisman  G. Fontana  M. Field  C. Mac Niocaill  R. S. J. Sparks  F. M. Stuart 《Bulletin of Volcanology》2012,74(7):1621-1643

The Igwisi Hills volcanoes (IHV), Tanzania, are unique and important in preserving extra-crater lavas and pyroclastic edifices. They provide critical insights into the eruptive behaviour of kimberlite magmas that are not available at other known kimberlite volcanoes. Cosmogenic ³He dating of olivine crystals from IHV lavas and palaeomagnetic analyses indicates that they are Upper Pleistocene to Holocene in age. This makes them the youngest known kimberlite bodies on Earth by >30?Ma and may indicate a new phase of kimberlite volcanism on the Tanzania craton. Geological mapping, Global Positioning System surveying and field investigations reveal that each volcano comprises partially eroded pyroclastic edifices, craters and lavas. The volcanoes stand <40?m above the surrounding ground and are comparable in size to small monogenetic basaltic volcanoes. Pyroclastic cones consist of diffusely layered pyroclastic fall deposits comprising scoriaceous, pelletal and dense juvenile pyroclasts. Pyroclasts are similar to those documented in many ancient kimberlite pipes, indicating overlap in magma fragmentation dynamics between the Igwisi eruptions and other kimberlite eruptions. Characteristics of the pyroclastic cone deposits, including an absence of ballistic clasts and dominantly poorly vesicular scoria lapillistones and lapilli tuffs, indicate relatively weak explosive activity. Lava flow features indicate unexpectedly high viscosities (estimated at >10² to 10⁶?Pa?s) for kimberlite, attributed to degassing and in-vent cooling. Each volcano is inferred to be the result of a small-volume, short-lived (days to weeks) monogenetic eruption. The eruptive processes of each Igwisi volcano were broadly similar and developed through three phases: (1) fallout of lithic-bearing pyroclastic rocks during explosive excavation of craters and conduits; (2) fallout of juvenile lapilli from unsteady eruption columns and the construction of pyroclastic edifices around the vent; and (3) effusion of degassed viscous magma as lava flows. These processes are similar to those observed for other small-volume monogenetic eruptions (e.g. of basaltic magma).  相似文献   

Analysis of surface circulation structures along a frequently repeated XBT transect crossing the Ligurian and Tyrrhenian Seas     

Tiziana Ciuffardi  Ernesto Napolitano  Roberto Iacono  Franco Reseghetti  Giancarlo Raiteri  Andrea Bordone 《Ocean Dynamics》2016,66(6-7):767-783

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Mapping and monitoring net primary productivity with AVHRR NDVI time-series: statistical equivalence of cumulative vegetation indices   总被引：1，自引：0，他引：1  

Carlo Ricotta  Giancarlo Avena  Alessandra De Palma 《ISPRS Journal of Photogrammetry and Remote Sensing》1999,54(5-6)

In the last two decades, numerous investigators have proposed cumulative vegetation indices (i.e., functions which encode the cumulative effect of NDVI maximum value composite time-series into a single variable) for net primary productivity (NPP) mapping and monitoring on a regional to continental basis. In this paper, we investigate the relationships among three of the most commonly used cumulative vegetation indices, expanding on the definition of equivalence of remotely sensed vegetation indices for decision making. We consider two cumulative vegetation indices as equivalent, if the value of one index is statistically predictable from the value of the other index. Using an annual time-series of broad-scale AVHRR NDVI monthly maximum value composites of the island of Corsica (France), we show that the pairwise linear association among the analysed cumulative vegetation indices shows coefficients of determination (R²) higher than 0.99. That is, knowing the value of one index is statistically equivalent to knowing the value of the other indices for application purposes.  相似文献   

Pollen Viability for Air Pollution Bio-Monitoring     

Elena Gottardini  Fabiana Cristofolini  Elena Paoletti  Paolo Lazzeri  Giancarlo Pepponi 《Journal of Atmospheric Chemistry》2004,49(1-3):149-159

Biological characterization of Corylus avellana L. and Pinus nigra L. pollen samples was carried out to determine the actual value of pollen as a bio-indicator of the effects of atmospheric pollution, using samples from plants naturally developed in sites controlled for air pollution. In Trentino (North Italy), we selected six stations at three different levels of air pollution, which are constantly monitored with automatic gauges by the Environmental Protection Agency of Trento.First results showed that pollen viability of both species, germinability and pollen tube length of P. nigra, were higher in areas with no road traffic compared to heavy traffic ones. Pollen viability of P. nigra was positively correlated to ozone (O₃) concentrations and altitude but negatively to sulphur dioxide (SO₂), particulate matter with a diameter less than 10 m (PM₁₀), nitrogen oxides (NO_x) and nitrogen dioxide (NO₂) concentrations.  相似文献   

A search for continuous ultraviolet opacity sources in the Sun's photosphere     

Egidio Landi Degl'Innocenti  Giancarlo Noci 《Solar physics》1973,29(2):287-297

Experimental results on limb darkening and specific intensities imply more ultraviolet continuous opacity than that predicted by theoretical calculations. Some atomic and molecular processes, not yet studied from this standpoint are investigated as to their importance on the continuous absorption coefficient. The negative results obtained suggest some arguments about the importance of iron as photo-absorber.  相似文献