http://hdl.handle.net/2122/53 2013-05-22T14:47:24Z http://hdl.handle.net/2122/8692 Title: Waveform Variation of the Explosion-Quakes as a function of the eruptive activity at Stromboli Volcano Authors: Esposito, A. M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; D'Auria, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Giudicepietro, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Martini, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia Editors: Apolloni, B.; Bassis, S.; Esposito, A.; Morabito, F.C. Abstract: In the period from June to September 2011, the Stromboli volcano was affected by an activity characterized by an increase of the volcanic tremor amplitude, in the magnitude of explosions and with some lava overflows. In order to examine and understand in more detail this particular phase of the volcano, we present here an unsupervised investigation of the waveform variation of the explosion-quakes recorded during this period. The aim is to identify a possible relationship between the temporal changes of these events and the volcano seismic activity. The analysis is performed on a dataset of about 8400 explosion-quakes by using a SOM neural network. This technique works well with large datasets allowing to find out unpredicted characteristics among them. The SOM clustering highlights sudden changes occurring at the end of July and of August and a permanent variation between June and September reflecting a modification in the volcano activity. These results could be interesting for focusing the analysis of the seismological dataset in these intervals in order to evidence minor, but important variations, which were previously undetected and to improve the knowledge on the explosive dynamics of the volcano. 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8688 Title: A unified 3D velocity model for the Neapolitan volcanic areas Authors: D'Auria, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Martini, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Esposito, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Ricciolino, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Giudicepietro, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia Editors: Marzocchi, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Zollo, A.; Università di Napoli Federico II Abstract: One of the main issues in seismic monitoring of active volcanic areas is the accurate location of earthquake hypocenters. Volcano-tectonic seismicity is often characterized by small magnitude swarms, recorded by few seismic stations with a high picking uncertainty. Sometimes events lacks clear S-wave arrivals, due to the nature of some volcanic sources. All these features, together with the complex crustal structure of volcanoes, makes the earthquake location problem critical in such areas. One of the most important effort for improving the quality of hypocenter location is the use of realistic 3D velocity models. In the last 10 years, several scientific papers proposed 2D and 3D velocity models for Mt. Vesuvius, Campi Flegrei and the Gulf of Naples. They comes from both active seismic data (VESUVIO 94, TOMOVES 96, MAREVES 97 and SERAPIS 2001 experiments) and from local earthquake tomography. In this report we propose a global unified velocity model spanning from Ischia island to Appennine Mts. that allows us to locate earthquakes in the Neapolitan volcanic areas and in the Gulf of Naples. This model comes from a weighted averaging of 5 tomographic velocity models and a background regional model. Most of the model provides only P-wave velocities, only 2 models, obtained through local earthquake tomography at Mt. Vesuvius and Campi Flegrei also gives a S-wave velocity estimate. We show the difference between this new model and the previous 1D models adopted for routine locations at INGV-Osservatorio Vesuviano. We also relocate some events, using non-linear techniques showing differences in hypocenter position from previous locations and the improvement in final traveltime residuals and location uncertainties. 2007-12-31T23:00:00Z http://hdl.handle.net/2122/8687 Title: Automatic analysis of seismic data by using Neural Networks: applications to Italian volcanoes Authors: Giudicepietro, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Esposito, A; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; D'Auria, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Martini, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Scarpetta, S.; Università di Salerno Editors: Marzocchi, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Zollo, A.; Università di Napoli Federico II Abstract: The availability of the new computing techniques allows to perform advanced analysis in near real time, improving the seismological monitoring systems, which can extract more significant information from the raw data in a really short time. However, the correct identification of the events remains a critical aspect for the reliability of near real time automatic analysis. We approach this problem by using Neural Networks (NN) for discriminating among the seismic signals recorded in the Neapolitan volcanic area (Vesuvius, Phlegraean Fields). The proposed neural techniques have been also applied to other sets of seismic data recorded in Stromboli volcano. The obtained results are very encouraging, giving 100% of correct classification for some transient signals recorded at Vesuvius and allowing the clustering of the large dataset of VLP events recorded at Stromboli volcano. 2007-12-31T23:00:00Z http://hdl.handle.net/2122/8671 Title: Possible model of electromagnetic signals before earthquakes Authors: Dudkin, F.; Lviv Centre of Institute for Space Research, Ukraine; Korepanov, V.; Lviv Centre of Institute for Space Research, Ukraine; Hayakawa, M.; University of Electro-Communications, Japan; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: Few days before many earthquakes a general change in the ratio of vertical to horizontal magnetic field components in the ULF band, often called “polarization”, has been observed that can be considered as a magnetic precursor of the subsequent earthquake. To explain such a specific behavior, we propose a simple model based on a linear current approximation depending on some assumption on the signal to noise ratio. This model is confirmed through a comparison that has been carried out between the experimental magnetic field data at Matsushiro (Japan, 1998.06.30, M=4.7) and Simeiz (Crimea, Ukraine, 1998.10.16, M=4.3 and 1998.10.18, M=4.3) earthquakes. About 1 – 2 days before these events we had recorded the anomalous decrease of the ratio of vertical to horizontal magnetic field components in Pc4 – Pc3 band. The NE-SW direction of the corresponding current linear model well agrees with the main tectonic feature of both seismogenic events. Additionally we also estimate the signal to noise ratio limits for the detection of ULF magnetic field components in Corralitos and Stanford campus for Loma Prieta (MS 7.1, 1989) earthquake. 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8662 Title: The Volcano-Seismic Clock of the South American Pacific Margin - A Possible First Link Between Natural Disasters Prevention and Expanding Earth Authors: Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Editors: Scalera, Giancarlo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Abstract: A volcano-seismic correlation was for a long time suspected to occur on the Pacific margin of South America. Scalera (2008) using the data available in 2006 in the Smithsonian Institution Catalogue of the volcanic eruptions, has revealed evidence that earthquakes happened into the South-American Wadati-Benio zone – with magnitude greater than 8.4 –are associated to an enhanced rate of volcanic eruptions, but has been impossible to determine the causal chain between the two phenomena. After 2006, the effort of the Smithsonian Institution to improve our knowledge of this region has resulted in a greatly increased completeness of the catalogue, adding the new eruptions for the 2000- 2010 interval, but also an additional 50% of new entries in the list of the Andean volcanoes. The occurrence of the Chilean earthquake of Maule – 27 February 2010 (M=8.8); occurred at five decades from the 1960 quake – has been the occasion to rework all the data searching for additional clues able to indicate a preferred causal direction eruptions-earthquakes or earthquakes-eruptions – or from a third more general cause (e.g. a mantle movements) to both eruptions and earthquakes. This short note discusses the three above-said hypotheses and tries to establish if these results could be useful to the aims of the Civil Protection in the programs of prevention and/or forecasting of natural disasters. 2012-11-30T23:00:00Z http://hdl.handle.net/2122/8661 Title: Biogenic/Abiogenic Hydrocarbons Origin - Possible Role of Tectonically Active Belts Authors: Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Editors: Scalera, Giancarlo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, Enzo; University of Bologna; Cwojdzinski, Stefan; Polish Geological Survey Abstract: The creation of hydrocarbons is linked to tectono-geologic processes and particularly to orogenesis, rifting, overthrusts, erosion, deposition of sediments, deep gas emissions, etc.. Many have claimed the inadequacy of plate tectonics in linearly explain a number of phenomena involved in hydrocarbons generation and geological processes, and many others have defended the synthesis of hydrocarbons starting from inorganic minerals, proposing di erent geochemical processes. In this paper a possible mechanism for production of abiogenic hydrocarbons is proposed, linking it to a previously proposed orogenic isostatic model. While in plate tectonics the cold slab travels in contact with the lithosphere of the continental side, oxidizing materials faced to oxidizing materials, in this model the hightemperature reducing environment of the undepleted mantle rises up and come in contact with the relatively cold oxidizing lithospheric environment. Non-lithostatic overpressures and a number of chemical reactions are then favoured in this sort of tectonic oxidizingreducing pile, leading to a multiple origin of the hydrocarbons. The actual situation along the Italian Apennines orogenic belt seems in accord to the proposed model in which an important role should have the abiogenic hydrocarbons in particular those produced by the tectonic working at the western margin of the Adriatic plate. However, albeit a continuous accumulation of abiogenic hydrocarbons is witnessed by a number of planetary bodies of the Solar system, still no evaluation of the abiogenic/biogenic hydrocarbons rate is possible on our planet. 2012-11-30T23:00:00Z http://hdl.handle.net/2122/8657 Title: Geodetic Problems of an Expanding Globe - Simple Critical Arguments Authors: Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Editors: Scalera, Giancarlo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, Enzo; University of Bologna; Cwojdzinski, Stefan; Polish Geological Survey Abstract: Because unequivocal evidence exist in favor of the expansion of the globe through geologic time, and if the expansion of our planetary body is ongoing today and not confined to the past or episodic in time, some subtle causes must consequently exist of the inability of Geodesy in revealing a plausible expansion rate. Old critical arguments around the possibility of a vicious circle in the geodetic theoretical methods (Blinov, 1987; Scalera, 2003) has revealed their inadequacy in respect of the geometry of space geodesy. On the bases of an old argument (Scalera, 2003), it has been then developed a new more realistic one, in which it is demonstrated that spurious effects can probably bias what is believed to be systematic-error-free data. It is argued that Geodesy still has to full develop a theoretical treatment of an expanding globe 2012-11-30T23:00:00Z http://hdl.handle.net/2122/8656 Title: If Space is Material, What Inertia Should Be? - Rediscovering a Dismissed Awareness of Ernst Mach Authors: Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Editors: Scalera, Giancarlo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, Enzo; University of Bologna; Cwojdzinski, Stefan; Polish Geological Survey Abstract: The ”Mach’s Principle” has beenconsidered for more than a century as the highest expression of the philosophical rationality of the western world, but it is possible to proof that it is built on a unstable ground and with uncomplete assumptions. With a great intellectual honesty, Ernst Mach showed in his works some awareness of the incompleteness of his reasoning about inertia. Moreover the Mach Principle is often misinterpreted by scientific community with an illegitimate extrapolation of the Mach words. 2012-11-30T23:00:00Z http://hdl.handle.net/2122/8655 Title: Distensional Mediterranean and World Orogens - Their Possible Bearing to Mega-Dykes Active Rising Authors: Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Editors: Scalera, Giancarlo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, Enzo; University of Bologna; Cwojdzinski, Stefan; Polish Geological Survey Abstract: An overview of the modern progresses of the expanding Earth conceptions as they come out from new data and their possible interpretations is provided in this paper. The starting point of this review is the new detailed 3D distributions of relocated hypocenters laying under orogenic belts. The similarity of the hypocentral patterns under the Tethyan orogenic belts, and under the South American Pacific orogenic margin is considered to be a major font of information on which to build a more realistic global geodynamic model. Clusters and filaments of hypocenters are recognizable instead of regular patterns. These clusters taper downwards, leading to the idea of a deep origin in narrow regions of disturbance, besides other important facts that witness in favour of surfaceward movements of deep material along what can be called "mega-dykes". The outpouring of the material on the surface produces gravitational nappes and their overthrust on the sediments of the preexisting trough, forcing them on a burial path which emulate the subduction process, but without reaching depths greater than 50-70 km. Phenomenons like metamorphism, mixing, migmization, upward transport of fragments of the buried lithosphere etc. are possible at the boundary between uplifting material and down-pushed crust and lithosphere. Additional clues can be collected that confirm the new proposed framework. The astronomical indications of a coseismic displacement of the instantaneous Earth’s rotation axis in the occasion of the great Sumatra (Mw=9.3) and Honshu (Mw=9.0) earthquakes are especially significant because in complete disagreement with the plate tectonics modelled axis shift and in agreement with the shift expected in the new conception. Because of analogous opposite predictions of the length of day variation following the extreme magnitude earthquakes (ΔLOD<0 vs ΔLOD>0), future improvements of the time measurement techniques could allow a final choice between rival geodynamical models. 2012-11-30T23:00:00Z http://hdl.handle.net/2122/8653 Title: The Earth Expansion Evidence – A Challenge for Geology, Geophysics, Astronomy and General Knowledge Authors: Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, E.; University of Bologna; Cwojdzinski, S.; Polish Geological Survey Editors: Scalera, Giancarlo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, Enzo; University of Bologna; Cwojdzinski, Stefan; Polish Geological Survey Abstract: The 37th Workshop of the International School of Geophysics held on 4-9 October 2011 in Erice (Sicily, Italy), was a long awaited occasion which allowed to gather the small scientific community of expansionists. Aims, results, discussions and varia umanità of this important event are presented thereafter. 2012-11-30T23:00:00Z