The understanding of the magma ascent mechanism has been investigated from early '70 and, up ... more The understanding of the magma ascent mechanism has been investigated from early '70 and, up to now, the proposed models are based on a fluid motion in a porous medium driven by the pore compaction and dilation. The basic equation is the well known Darcy's law: it states that the liquid flux through a permeable matrix is proportional to the
ABSTRACT The investigate the aftershock decay soon after the largest ten sequences occurred in So... more ABSTRACT The investigate the aftershock decay soon after the largest ten sequences occurred in Southern California in last 20 years. We show that this decay becomes independent on the mainshock magnitude M(M) and on the lower magnitude threshold M(I) if time is rescaled by an appropriate time scale fixed by the difference M(M) M(I). This result supports the idea that the missing of recorded earthquakes in first part of aftershock sequences is not an artefact due to catalog incompleteness but a real physical effect. We show that a recently proposed dynamical scaling relationship can reproduce the aftershock decay experimentally observed. This approach gives prediction also in agreement with recent results for the organization of aftershocks after small or intermediate magnitude mainshock in Japan.
An increase in the number of smaller magnitude events, retrospectively named foreshocks, is often... more An increase in the number of smaller magnitude events, retrospectively named foreshocks, is often observed before large earthquakes. We show that the linear density probability of earthquakes occurring before and after small or intermediate mainshocks displays a symmetrical behavior, indicating that the size of the area fractured during the mainshock is encoded in the foreshock spatial organization. This observation can be used to discriminate spatial clustering due to foreshocks from the one induced by aftershocks and is implemented in an alarm-based model to forecast m > 6 earthquakes. A retrospective study of the last 19 years Southern California catalog shows that the daily occurrence probability presents isolated peaks closely located in time and space to the epicenters of five of the six m > 6 earthquakes. We find daily probabilities as high as 25% (in cells of size 0.04 × 0.04deg(2)), with significant probability gains with respect to standard models.
Via Molecular Dynamics simulations, we investigate the stick-slip motion in a model of fault, whe... more Via Molecular Dynamics simulations, we investigate the stick-slip motion in a model of fault, where two surfaces subject to a constant confining pressure P, and enclosing granular particles, are subject a shear stress sigma. When the system sticks, the stress increases with a constant rate ˙ sigma , while the stress decreases when the system flow. We dermine the system
The discussion about the source of low frequency events generally wrecorded on active volcanoes i... more The discussion about the source of low frequency events generally wrecorded on active volcanoes is still open and needs deeper understanding of the phenomena involved in their generation. Most of the models view such a phenomenon as a source effect (oscillation of ...
The understanding of the magma ascent mechanism has been investigated from early '70 and, up ... more The understanding of the magma ascent mechanism has been investigated from early '70 and, up to now, the proposed models are based on a fluid motion in a porous medium driven by the pore compaction and dilation. The basic equation is the well known Darcy's law: it states that the liquid flux through a permeable matrix is proportional to the
ABSTRACT The investigate the aftershock decay soon after the largest ten sequences occurred in So... more ABSTRACT The investigate the aftershock decay soon after the largest ten sequences occurred in Southern California in last 20 years. We show that this decay becomes independent on the mainshock magnitude M(M) and on the lower magnitude threshold M(I) if time is rescaled by an appropriate time scale fixed by the difference M(M) M(I). This result supports the idea that the missing of recorded earthquakes in first part of aftershock sequences is not an artefact due to catalog incompleteness but a real physical effect. We show that a recently proposed dynamical scaling relationship can reproduce the aftershock decay experimentally observed. This approach gives prediction also in agreement with recent results for the organization of aftershocks after small or intermediate magnitude mainshock in Japan.
An increase in the number of smaller magnitude events, retrospectively named foreshocks, is often... more An increase in the number of smaller magnitude events, retrospectively named foreshocks, is often observed before large earthquakes. We show that the linear density probability of earthquakes occurring before and after small or intermediate mainshocks displays a symmetrical behavior, indicating that the size of the area fractured during the mainshock is encoded in the foreshock spatial organization. This observation can be used to discriminate spatial clustering due to foreshocks from the one induced by aftershocks and is implemented in an alarm-based model to forecast m > 6 earthquakes. A retrospective study of the last 19 years Southern California catalog shows that the daily occurrence probability presents isolated peaks closely located in time and space to the epicenters of five of the six m > 6 earthquakes. We find daily probabilities as high as 25% (in cells of size 0.04 × 0.04deg(2)), with significant probability gains with respect to standard models.
Via Molecular Dynamics simulations, we investigate the stick-slip motion in a model of fault, whe... more Via Molecular Dynamics simulations, we investigate the stick-slip motion in a model of fault, where two surfaces subject to a constant confining pressure P, and enclosing granular particles, are subject a shear stress sigma. When the system sticks, the stress increases with a constant rate ˙ sigma , while the stress decreases when the system flow. We dermine the system
The discussion about the source of low frequency events generally wrecorded on active volcanoes i... more The discussion about the source of low frequency events generally wrecorded on active volcanoes is still open and needs deeper understanding of the phenomena involved in their generation. Most of the models view such a phenomenon as a source effect (oscillation of ...
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