The Nirano Salse in Italy is a well-studied site where natural gas seepage (NGS) and other hydrocarbon fluids gases are emitted at the earth's surface. A novel integrated approach applied to define comprehensive structural interpretation of flow dynamic mud volcano system Regional Nature Reserve (Modena, Northern Apennines). paper investigates relationship between emissions local structures, particularly faults fractures, shallow subsurface (down 500–600 m depth) understand control that...

The formation of lava tubes is a common phenomenon on some basaltic volcanoes, such as Etna. A model for tube by roofing channel proposed and involves first describing Bingham liquid flowing down slope. It further assumed that flows in with rectangular cross section: result heat loss into the atmosphere, crust gradually formed upper surface flow this eventually welds to levées. We assume when sufficiently thick resist drag underlying sustain itself under its own weight. minimum thickness...

It is generally agreed that the occurrence of seismic sequences implies a kind interaction between different fault segments. The coseismic stress transfer produced by each dislocation most obvious component such an interaction. However, time intervals elapsing subsequent events in sequence indicate not sufficient to trigger other itself. We investigate possibility field may induce flow pore fluids, altering pressure distribution region. Since crust fluid-saturated medium at many locations,...

Okada (1992) provided expressions for the displacement and strain fields due to a finite rectangular source in an elastic, homogeneous isotropic half-space. Starting with these results, we applied correspondence principle of linear viscoelasticity derive quasi-static displacement, stress viscoelastic, We assume that medium deforms viscoelastically respect both shear normal stresses but keeps constant bulk modulus; particular, modulus relaxes as Maxwell fluid. presented viscoelastic effect on...

During the emplacement lava behaves as a non‐Newtonian, pseudoplastic fluid. Laboratory experiments on samples suggest that power‐law constitutive equation may be appropriate. We consider horizontally unbounded, isothermal layer of lava, flowing down slope driven by gravity force. where shear stress is proportional to strain rate raised power n , ranging from 0 1, and we take into account temperature dependence rheological parameters. Formulae are obtained relating rheology geometric dynamic...

Abstract In many basaltic eruptions, observations show that the effusion rate of magma has a typical dependence on time: curves first period increasing and later decreasing phase by maximum value. We present model to explain this behavior emptying reservoir through vertical cylindrical conduit with elliptical cross section, coupled its widening due mechanical erosion, produced flow. The can reproduce observed time in eruptions. Eruption duration value depend size chamber, lava viscosity...

Abstract The debate about the conceptual model of mud volcanoes functioning is still alive in literature. A large part literature focuses on characterization deep reservoir where expelled fluids are expected to originate. Another focused study shallow system volcanoes, which could influence short‐term variations activity. We present and analyze a new data set micro‐gravimetric area Nirano Salse , Italy. Unlike what commonly assumed for area, our results suggest that geomorphology not related...

Abstract The Nirano Salse , known since the Roman Times, are one of most beautiful and scenic mud volcanoes areas Italy with thousands visitors every year. In this work, we apply novel (for context) hydrogeological techniques to characterize levels in by means GPS-RTK positioning continuous level logging within conduits. This is important quantify gas–liquid ratio conduits evaluate potential for dangerous abrupt eruptions. results presented suggest that different clusters due not necessarily...

Abstract. Mud volcanoes are fluid escape structures allowing for surface venting of hydrocarbons (mostly gas but also liquid condensates and oils) water–sediment slurries. For a better understanding mud volcano dynamics, the characterization dynamics within conduits; presence, extent, depth reservoirs; connection among aquifers, conduits, reservoirs play key role. To this aim, we performed geoelectrical survey in Nirano Salse Regional Nature Reserve, located at edge northern Apennines...

The Nirano Salse in Italy is a well-studied site where natural gas seepage (NGS) and other hydrocarbon fluids gases are emitted at the earth's surface. A novel integrated approach applied to define comprehensive structural interpretation of flow dynamic mud volcano system Regional Nature Reserve (Modena, Northern Apennines). paper investigates relationship between emissions local structures, particularly faults fractures, shallow subsurface (down 500-600 m depth) understand control that...

Abstract. The behaviour of seismogenic faults is generally investigated under the assumption that they are subject to a constant strain rate. We consider effect slowly variable rate on recurrence times earthquakes generated by single fault. To this aim spring-block system employed as low-order analog Two cases considered: sinusoidal oscillation in driver velocity and monotonic change from one value another. In first case, study orbit state space suggests seismic activity equivalent fault...

We present here the results from dynamical and thermal models that describe a channeled lava flow as it cools by radiation. In particular, effects of power-law rheology presence bends in are considered, well formation surface crust tubes. On basis models, we analyze assumptions implicit currently used formulae for evaluation rates satellite imagery. Assuming steady down an inclined rectangular channel, solve numerically equation motion finite-volume method classical iterative solution. Our...

Abstract We study the thermomechanical evolution of a stationary lava body cooling from upper surface. The progressively solidifies and develops boundary layer made an solid thermoelastic crust lower viscoelastic layer. presented approach to problem is one‐dimensional quasi‐static. Under assumption that brittle with given strength, we generation tensile fractures. consider single fracture event assume produced when thermal stress exceeds strength over certain depth interval, inferred...

Time-dependent piezomagnetic fields due to inclined rectangular faults embedded in a viscoelastic, homogeneous half-space were investigated. A viscoelastic rheology of the surrounding medium was assumed relate changes at surface stress field depth. The viscosity strongly influences time-dependent changes. Especially volcanic areas, rocks near magmatic sources are considerably heated. presence higher temperatures produces lower effective crust, making it necessary consider its inelastic...

During 1997 several slow earthquakes have been recorded by a geodetic interferometer located beneath Gran Sasso, central Italy. The strain rise times of the events range from tens to thousands seconds and amplitudes are order 10−9. Amplitudes scale with square root time this suggests diffusive behaviour slip propagation along fault. In work, we develop model in which diffusion is result presence gouge layer between fault faces, viscoplastic rheology. fluid velocity field diffuses directions...

Abstract We assume that a magma pulse enters chamber from the plumbing system, producing an overpressure triggering effusive volcanic eruption. The is modeled as spherical cavity in elastic half‐space, connected to Earth's surface by vertical conduit, and incompressible Newtonian liquid. Overpressure calculated function of time during eruption has different behaviors depending on characteristics system. history effusion rate controlled duration geometrical rheological parameters model. rates...

Abstract Effusion rate in basaltic eruptions typically depends on time: there is an initial, relatively fast increase followed by a much slower decrease until the eruption vanishes; addition, changes are observed effusion having durations shorter than total duration of eruption. For effusive eruption, we calculate deformation volcanic conduit due to short‐term pressure oscillations. The model considers elliptical embedded viscoelastic medium, described Maxwell body. As consequence...

Abstract The Nirano Salse , known since the Roman Times, are one of most beautiful and scenic mud volcanoes areas Italy with thousands visitors every year. In this work, we apply hydrogeological techniques to characterize levels in by means GPS-RTK positioning continuous level logging within conduits. Our results suggest that different clusters due gas-liquid ratio conduits not necessarily exclude interconnection at depth, a hypothesis, on other hand, seems strengthened time series...