DSpace Collection:http://hdl.handle.net/2122/3882024-03-05T10:30:54Z2024-03-05T10:30:54ZEarthquakes, volcanic eruptions and geodynamics: a 'box for thinking and working'Fregonese, R.http://hdl.handle.net/2122/79902022-04-21T08:41:06Z2012-06-22T00:00:00ZTitle: Earthquakes, volcanic eruptions and geodynamics: a 'box for thinking and working'
Authors: Fregonese, R.
Abstract: After reviewing the main results present in the literature on geodynamic toward seismic and volcanic activity and risks, the paper present a causative global model of these phenomena and delineates a model of calculus for earthquakes and volcanic eruptions prediction. The model involves a mechanical schematization of the entire globe, make use of Somigliana’s identity and gives results in terms of probabilities given the PDF of mechanical parameters like Lamè’m on fault
planes and viscosity of the magmas.
The results then can be updated with short and long term precursors.2012-06-22T00:00:00ZSelf-sustained oscillations at Volcan de Colima (Mexico) inferred by Independent Component AnalysisDe Lauro, E.De Martino, S.Palo, M.Ibanez, M. J.http://hdl.handle.net/2122/65752020-12-15T11:56:09Z2011-01-12T00:00:00ZTitle: Self-sustained oscillations at Volcan de Colima (Mexico) inferred by Independent Component Analysis
Authors: De Lauro, E.; De Martino, S.; Palo, M.; Ibanez, M. J.
Abstract: We have analyzed Long-Period (LP) seismic events of Volcan de
Colima (Mexico) recorded by four three-component broad-band seismometers
during January 2006. Frequency-domain analysis shows broad-band spectra
mainly in the range 0.3-2 Hz characterized by a monotonic decreasing envelope,
as those observed in a cylindrically-symmetric self-oscillating cavity interacting
with a confined jet. Independent Component Analysis, a time decomposition
method extracts two or three nonlinear oscillation modes depending on the
station, with the fundamental one peaked at [0.4-0.5]Hz. These decomposed
waves are self-sustained oscillations with low dimensionality and a well defined
spectral content. Moreover, they show radial polarization in near field and
transverse polarization in far field in North-West South-East direction. Finally, we depict a branched plumbing system with two principal conduits directed along orthogonal directions.2011-01-12T00:00:00ZSurface circulation in the Liguro-Provençal basin as measured by satellite-tracked drifters (2007-2009)Poulain, P-M.Gerin, R.Rixen, M.Zanasca, P.Teixeira, J.Griffa, A.De Marte, M.Pinardi, N.http://hdl.handle.net/2122/58462017-04-04T04:08:25Z2010-01-01T00:00:00ZTitle: Surface circulation in the Liguro-Provençal basin as measured by satellite-tracked drifters (2007-2009)
Authors: Poulain, P-M.; Gerin, R.; Rixen, M.; Zanasca, P.; Teixeira, J.; Griffa, A.; De Marte, M.; Pinardi, N.
Abstract: The surface circulation in the Liguro-Provençal basin (Northwestern Mediterranean)
is studied using satellite-tracked drifters in 2007-2009. Complex circulation patterns
prevailed in the eastern Ligurian Sea, before the drifters eventually joined the
Northern Current (NC) in the coastal area off Genoa. Between 5°E and 7°E30’, most
drifters were advected offshore before heading to the east and eventually closing a
basin-wide cyclonic circulation. This offshore turning is related to the wind and wind
stress curl during Mistral events. Although the Western Corsican Current was well
delineated by the drifters, no signature of the Eastern Corsican Current was shown,
indicating limited connectivity between the Tyrrhenian and Ligurian seas in summer
2007. Pseudo-Eulerian velocity statistics were calculated in the coastal region
extending between Genoa and the Gulf of Lyons. Fast currents are evident on the
shelf break, especially off Imperia (maximum of 90 cm/s) where the bathymetric
slope is larger and the NC is closer to shore and narrower. In contrast, a stagnation
area inshore of the NC near Fréjus is characterized by little mean flow and low
velocity fluctuations. Mean currents are also reduced off Menton-Nice where the
variability is maximum. More to the west, the NC broadens and slightly reduces in
strength.2010-01-01T00:00:00ZA numericla study of the mescale variability in the Adriatic SeaOddo, P.Pinardi, N.http://hdl.handle.net/2122/38192017-04-03T23:57:10Z2008-01-01T00:00:00ZTitle: A numericla study of the mescale variability in the Adriatic Sea
Authors: Oddo, P.; Pinardi, N.
Abstract: The Adriatic Sea mesoscale and its inter-annual variability is investigated by means of a high-resolution numerical ocean model with approximately 2 km resolution. The ocean model used is based on the Princeton Ocean Model (POM, Blumberg and Mellor 1987) which has been modified in the advection scheme and the vertical velocity surface boundary condition. The simulation spans 6 years starting from January 1999 till December 2004. The surface forcing is interactively computed using European Centre for Medium Range Weather Forecast (ECMWF) operational atmospheric fields and climatological precipitation, while river runoff is obtained combining daily Po river (the main Adriatic river) data together with climatological estimates for all the other rivers. The model results have been validated by an extended comparison with in situ and remote sensing observations.
The simulated variability exhibits evident similarities with the actual mesoscale variability, in terms of location, nature and temporal evolution of the features. The major results concern the spatial and temporal variability of Eddy and Mean Kinetic Energy (EKE and MKE) and the baroclinic energy conversion term contained in the buoyancy work time rate. We show for the first time evidence of baroclinic instability at the level of major sub-basin scale structures such as the Western Adriatic Coastal Current. Furthermore, the seasonal and inter-annual variability of mean and eddy kinetic energy is correlated with surface forcing (wind stress work) and Po runoff.2008-01-01T00:00:00Z