Volcanic rocks forming sills, dykes or lava flows may display a magnetic anisotropy derived from the viscous flow during their emplacement. We model sill as steady-state of Bingham fluid, driven by pressure gradient in horizontal conduit. The magma velocity function depth is calculated motion and constitutive equations. Vorticity strain rate are determined for reference system moving with fluid. angular orientation an ellipsoidal grain immersed fluid functions time strain. Magnetic...

On 23 March 2018, an event of magnitude ML 3.9 occurred about 10 km from the town Ostuni, in Adriatic offshore. It was most energetic earthquake South–Central Apulia ever recorded instrumentally. 13 February 2019, same area, a second 3.3 recorded. The analysis 2018 shows that ambiguity solution fault plane reported by INGV (Istituto Nazionale di Geofisica e Vulcanologia) on Italian National Earthquake Centre website can be solved considering existing seismic profiles, exploration well logs...

Enriching seismic network catalogues is a key object to understand the seismotectonic processes and hazard. In areas with poor knowledge of patterns, installation dense local networks essential. The enhanced density coverage improves detection events low energy. Nowadays, Machine Learning (ML) techniques are becoming widely used in seismology, addition standard automatic procedures (i.e., STA/LTA-based algorithms).In this study, we assess performance P- S-wave picking earthquake algorithms...

The availability of high‐resolution thermal imagery active lava flows has stimulated the use radiance maps for evaluation effusion rates. This is made possible by simple formulae relating flow rate to energy radiated per unit time from planimetric surface flow. Such are based on a specific model and, consequently, their validity subject assumptions. An analysis these assumptions reveals that current not consistent with model. reason why they provide reasonable, although very rough, values...

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...

Abstract Fluid‐induced seismicity has been a particularly emphasized mechanism over the last few years, especially after fluid‐related, moderate‐to‐large earthquakes have observed in several locations around globe. Several studies suggest that relationships between and fluid presence are related to variations stress state of rocks, due increase or drop pore pressure. In this scenario, Val d’Agri represents precious case study where fluid‐induced is observed. area, two seismic clusters...

Historical seismic catalogs report that the Gargano Promontory (southern Italy) was affected in past by earthquakes with medium to high estimated magnitude. From instrumental seismicity, it can be identified most energetic Apulian sequence occurred 1995 a main shock of M W = 5.2 followed about 200 aftershocks maximum magnitude 3.7. The are attributed right-lateral strike-slip faults, while there is evidence present-day seismicity occur on thrust or thrust-strike faults. In this article, we...

We propose a three‐dimensional (3‐D) Bingham model for channeled lava flow. Unlike from the 3‐D Newtonian models, this can be applied also far vent where rheology cannot neglected as consequence of cooling. assume to an isothermal liquid flowing in rectangular channel down constant slope. The flow velocity is calculated by solving semianalytically steady state Navier‐Stokes equation together with constitutive equation. vorticity evaluated and used define plug shape position different flows:...

We propose a model to describe lava tube formation, considering as Newtonian fluid moving downslope in rectangular channel. obtain flow velocity using an analytical steady‐state solution of the Navier‐Stokes equation. Shear stress is also calculated from for incompressible and isotropic fluid. A 2‐D with heat flux assigned at upper surface introduced cooling by radiation into atmosphere temperature. Lava crust considered plastic body, its rheology described through introduction yield...

Recent laboratory studies on the rheology of lava samples from different volcanic areas have highlighted that apparent viscosity depends a power strain rate. Several authors agree in attributing this dependence to crystal content sample and temperature. Starting these results, paper we studied effect law gravity‐driven flow. The equation motion is nonlinear diffusion term, an analytical solution does not seem be possible. finite‐volume method has been applied solve numerically governing...

We estimate the long‐term vertical deformation of Basiluzzo island, located in volcanic arc Aeolian Islands, Italy, by inferring subsidence a Roman age submerged wharf dated 2000 ± 50 years ago. model crustal that produced this displacement as cooling magma chamber emplaced during formation island. This is first attempt to using archaeological structure. Nowadays top wharf, which can be considered an unconventional leveling benchmark, near Punta Levante, at average depth 3.20 0.10 m below...

The shape of the front a lava flow is controlled by forces acting on and, in turn, controls dynamics. We present an analysis advancing flow, considering both Newtonian fluid and Bingham fluid, which most commonly used non‐Newtonian rheological model for lava. assume than moving at constant velocity sloping plane. considered as having infinite extent perpendicularly to direction, so that problem two‐dimensional. producing advance are gravity force pressure gradient due curvature surface....

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...

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...

The University of Bari (Italy), in cooperation with the National Institute Geophysics and Volcanology (INGV) has installed OTRIONS micro-earthquake network to better understand active tectonics Gargano promontory (Southern Italy). operates since 2013 consists 12 short period, 3 components, seismic stations located Apulian territory This data article releases waveform database collected from 2018 describes characteristics local current configuration. At end 2018, we implemented a cloud...

The effusion rate of lava from a volcanic vent is an important quantity controlling the length ensuing flow. ability to evaluate therefore importance estimate hazard connected with In present paper we provide formulae giving and viscosity for two‐ three‐dimensional (3‐D) Newtonian Bingham flows. order keep difference between actual model estimation within 10%, 3‐D must be used if ratio width thickness flow does not exceed value 13. plug exceeds 0.07. An analogous consideration can made viscosity.

The cooling of a lava flow, both in the transient and steady state, is investigated considering that rheology pseudoplastic dependent on temperature. Lava exits from vent with constant velocity flows down slope under effect gravity force inside channel rectangular cross section. We consider caused by thermal radiation into atmosphere conduction at walls ground. heat equation solved numerically 3‐D computational domain, solution tested to evaluate numerical errors. study state initial period...