Search results for "MICI"
showing 10 items of 1671 documents
Nonlinear nystagmus processing causes torsional VOR nonlinearity.
2003
The eye movement component that rotates around the line of sight, i.e., the ocular torsion, is in many aspects different from horizontal and vertical eye movements. While ocular torsion is mediated only by reflexive pathways like the torsional vestibulo-ocular and optokinetic reflexes (TVOR and OKN, respectively), horizontal and vertical components are also subject to intentional control mechanisms that are mediated by the saccadic and the pursuit systems. Dynamic properties of torsional eye movements are also very distinct. While horizontal and vertical VOR components show a gain close to unity and a small neural integration leakage with a time constant around pi=30 s, the TVOR shows a sma…
Radon measurements in the SE and NE flank of Mt. Etna (Italy)
2007
Abstract Soil Radon has been monitored at two fixed sites located in the northeastern and southeastern flank of Mt. Etna. In this study we report the comparison between in-soil Radon concentration trend recorded in the SE flank and that one recorded in the NE one, where an in-soil Radon detection system is operating since 2001. The aim of this work was to implement the investigation area finding a suitable radon detection site, in the south-east flank of Mt. Etna, in order to better understand possible links between Radon anomalies and volcano dynamic. Radon data collected in NE and SE sites were compared with the volcanic tremor, frequency of occurrence of earthquakes and seismic strain-re…
Recent Activity and Kinematics of the Bounding Faults of the Catanzaro Trough (Central Calabria, Italy): New Morphotectonic, Geodetic and Seismologic…
2021
A multidisciplinary work integrating structural, geodetic and seismological data was performed in the Catanzaro Trough (central Calabria, Italy) to define the seismotectonic setting of this area. The Catanzaro Trough is a structural depression transversal to the Calabrian Arc, lying in-between two longitudinal grabens: the Crati Basin to the north and the Mesima Basin to the south. The investigated area experienced some of the strongest historical earthquakes of Italy, whose seismogenic sources are still not well defined. We investigated and mapped the major WSW–ENE to WNW–ESE trending normal-oblique Lamezia-Catanzaro Fault System, bounding to the north the Catanzaro Trough. Morphotectonic …
Passive vs. active degassing modes at an open-vent volcano (Stromboli, Italy)
2012
Abstract We report here on a UV-camera based field experiment performed on Stromboli volcano during 7 days in 2010 and 2011, aimed at obtaining the very first simultaneous assessment of all the different forms (passive and active) of SO 2 release from an open-vent volcano. Using the unprecedented spatial and temporal resolution of the UV camera, we obtained a 0.8 Hz record of the total SO 2 flux from Stromboli over a timeframe of ∼14 h, which ranged between 0.4 and 1.9 kg s −1 around a mean value of 0.7 kg s −1 and we concurrently derived SO 2 masses for more than 130 Strombolian explosions and 50 gas puffs. From this, we show erupted SO 2 masses have a variability of up to one order of mag…
Tectonics and seismicity of the Tindari Fault System, southern Italy: Crustal deformations at the transition between ongoing contractional and extens…
2006
[1] The Tindari Fault System (southern Tyrrhenian Sea, Italy) is a regional zone of brittle deformation located at the transition between ongoing contractional and extensional crustal compartments and lying above the western edge of a narrow subducting slab. Onshore structural data, an offshore seismic reflection profile, and earthquake data are analyzed to constrain the present geometry of the Tindari Fault System and its tectonic evolution since Neogene, including the present seismicity. Results show that this zone of deformation consists of a broad NNW trending system of faults including sets of right-lateral, left-lateral, and extensional faults as well as early strike-slip faults rewor…
An integrated approach to investigate the seismotectonics of northern Sicily and southern Tyrrhenian
2009
Abstract This paper deals with a comparison among recent structure and seismicity in the hinge zone between northern Sicily and southern Tyrrhenian, corresponding to both emerged and submerged northern portion of the Maghrebian chain. This hinge zone is part of a wider W–E trending right-lateral shear zone, mainly characterized by both a synthetic NW-SE/W–E oriented, and antithetic left-lateral N–S/NE-SW fault systems, which has been affecting the tectonic edifice, since the Pliocene. The inland structures have been mapped using aerial-photo interpretation, geological mapping and mesostructural analysis to reconstruct the stress regime in the study area. On the contrary, the offshore struct…
Active north-vergent thrusting in the northern Sicily continental margin in the frame of the quaternary evolution of the Sicilian collisional system
2021
Abstract A three-stage evolution has characterized the Sicilian Fold and Thrust Belt (SFTB) during the last 15 My: two main thin-skinned shortening events involving mainly Meso-Cenozoic carbonate units, followed by thick-skinned thrusting involving Plio-Pleistocene deposits in the frontal area as well as the crystalline basement in the inner and deeper sector of the chain. We investigated the northern Sicily continental margin, by using differently-penetrative seismic reflection data and new field surveys, which revealed, both offshore and onshore, north-vergent compressional structures that affected the tectonic edifice during Quaternary time. These structures, correlated with the kinemati…
The Problem of Volcanic Unrest: The Campi Flegrei Case History
1996
Campi Flegrei is one of the most densely populated active volcanic areas of the world. It consists of a complex structure with a multicollapse caldera and many postcaldera, explosive, mostly monogenetic vents. The last eruption was in 1538 (Mt. Nuovo). Progressive reduction of eruption energy has accompanied migration of the vents toward the center of the caldera. Campi Flegrei activity is fed by a shallow magma chamber in which trachybasaltic magma undergoes cooling and fractionation, producing trachytic residual melt that is periodically tapped and erupted to the surface. The depth of the chamber is estimated, from petrological and active and passive seismic data, to be about 4 km beneath…
Flow changes and geochemical anomalies in warm and cold springs associated with the 1992-1994 seismic sequence at Pollina, Central Sicily, Italy
2007
During a three-year discontinuous geochemical monitoring of some warm springs and cold discharges located in central-northern Sicily, some hydro-geochemical changes were observed. Excluding a possible related to a moderate seismic activity were accidentally identified. The observed anomalies showed amplitudes that were modulated by the different geometries and volumes of the feeding aquifers. A poroelastic aquifer contraction, a shaking-induced dilatancy theory as well as seismogenetic-induced changes in the properties of the aquifers have been proposed as possible mechanisms for the water flow and hydro-geochemical changes. These preliminary results could be used to design a monitoring net…