Search results for "Volcano"
showing 10 items of 591 documents
The INGV's new OBS/H: Analysis of the signals recorded at the Marsili submarine volcano
2009
Abstract The ocean bottom seismometer with hydrophone deployed on the flat top of the Marsili submarine volcano (790 m deep) by the Gibilmanna OBS Lab (CNT–INGV) from 12th to 21st July, 2006, recorded more than 1000 transient seismic signals. Nineteen of these signals were associated with tectonic earthquakes: 1 teleseismic, 8 regional (located by INGV) and 10 small local seismic events (non located earthquakes). The regional events were used to determine sensor orientation. By comparing the signals recorded with typical volcanic seismic activity, we were able to group all the other signals into three categories: 817 volcano–tectonic type B (VT-B) events, 159 occurrences of high frequency t…
Monochromatic Long-Period Seismicity Prior to the 2012 Earthquake Swarm at Little Sitkin Volcano, Alaska
2021
Detection of the earliest stages of unrest is one of the most challenging and yet critically needed aspects of volcano monitoring. We investigate a sequence of five unusual long-period (LP) earthquakes that occurred in the days prior to the onset of a months-long volcano-tectonic (VT) earthquake swarm beneath Little Sitkin volcano in the Aleutian Islands during late 2012. The long-period earthquakes had two distinctive characteristics: their signals were dominated by a monochromatic spectral peak at approximately 0.57 Hz and they had impulsive P and S-wave arrivals on a seismometer located on Amchitka Island 80 km to the southeast of the volcano. In each case, the monochromatic earthquakes …
Structural architecture and active deformation pattern in the northern sector of the Aeolian-Tindari-Letojanni fault system (SE Tyrrhenian Sea-NE Sic…
2017
Framed in the current geodynamics of the central Mediterranean, the Aeolian-Tindari-Letojanni fault system is part of a wider NW-SE oriented right-lateral wrench zone which accommodates diverging motion between regional-scale blocks located at the southern edge of the Calabrian Arc. In order to investigate the structural architecture and the active deformation pattern of the northern sector of this tectonic feature, structural observations on-land, high and very-high resolution seismic reflection data, swath bathymetry data and seismological and geodetic data were merged from the Lipari-Vulcano volcanic complex (central sector of the Aeolian Islands) to the Peloritani Mountains across the G…
Evidences of mud volcanoes in the Palermo and Termini Gulf (N Sicily offshore)
2009
The occurrence of mud volcanoes and mud domes is, for the first time, documented in the continental shelf and upper slope of the Palermo and Termini Gulf (north Sicily offshore region). The study area belongs to the northern Sicily continental margin (southern Tyrrhenian Sea). Along this margin, morphology of the high-gradient continental slope is irregular due to the presence of structural highs, slope failures and canyons, and is interrupted by a flat area at a depth of 1,500 m. Mud volcano activity generally formed in areas characterised by high sedimentation rates and/or as consequences of regional tectonics (often compressional), overpressure in the sediments and gas generated at diffe…
Active volcano-tectonic deformations: a 3D seismic reflection experiment in the resurgent dome of the NYT Caldera (Pozzuoli Bay, Campi Flegrei, Naple…
2018
An ultra-resolution, 3D seismic reflection data cube was collected during an oceanographic cruise organized in the frame of a joint project involving Italian research institutions, the University of Palermo, Catania and Napoli, CNR of Napoli and INGV Roma, and two companies, the Geo Marine Survey System (The Netherlands) and GeoSurvey (Portugal). The data acquisition approach charted during this cooperation was based on innovative technologies for the offshore imaging of stratigraphy and structures at continental margins with horizontal and vertical resolution at decimetric scale. In this work, we present the methodology used for the 3D HR-seismic reflection data acquisition and the prelimi…
The use and beauty of ultra-high-resolution seismic reflection imaging in Late Quaternary marine volcaniclastic settings, Napoli Bay, Italy
2019
A Nápolyi-öbölben felvett ultra nagy felbontású egycsatornás (IKB-Seistec™) reflexiós szeizmikus szelvények korábbi geológiai és geofizikai vizsgálatok eredményeivel együtt kivételes, eddig soha nem látott felbontású szeizmikus leképezését nyújtják a Flegrei-mezők és a Somma-Vezúv felszín alá süllyedt késő-pleisztocén–holocén rétegtani felépí - tésének. A szeizmikus szelvényeken látott geometria és gravitációs magvevővel nyert üledékek adatainak összevetéséből Campania partközeli kontinentális talapzatán számos olyan üledékes és vulkáni szerkezet, valamint hidrotermális jelenség került leképezésre, melyek a legutolsó glaciális maximum (kb. 18 000 év) óta keletkeztek. A Pozzuoli-öbölben mért…
On the relationships between tectonics and volcanism in the offshore capo vaticano, se tyrrhenian sea, during the plio-pleistocene.
2014
High-resolution bathymetry and a grid of single-channel reflection seismic profiles (Sparker and Chirp) were recently recorded in a sector of the upper slope of Capo Vaticano (CV) promontory (Tyrrhenian coast, W Calabria) where forward and inverse modeling of previously acquired aeromagnetic data highlight the presence of a WNW©\ESE elongated, 20 km long and 3¨C5 km wide, magnetized body extending from sea floor to about 3 km below sea level. Magnetic properties of this body are consistent with those of the medium to highly evolved volcanic rocks of the Aeolian Arc (De Ritis et al., 2010). Forthwith offshore promontory, the bathymetry highlights a complex-shape seamount that develops along …
The transition between the Marsili oceanic crust and the W Calabria rifted margin: rifting and drifting in the upper plate of the Ionian subduction z…
2012
The western Calabria continental margin forms the transition between the Late Pliocene to Recent Marsili spreading center and continental Calabria. Integrating highpenetration and -resolution upper crustal seismic images with seafloor morphology, ODP well data and geological/geophysical constraints we provide a detailed reconstruction of the architecture of the distal portion of the W Calabria rifted margin and of the adjacent Marsili “oceanic” domain (Fig. 1) and develop a scheme for the Pliocene to present rifting and drifting of the upper plate of the Ionian subduction zone. Our seismic data document the presence of stretched and thinned continental crust, less than 10 Km thick into the …