http://hdl.handle.net/2122/195 2013-05-25T13:50:59Z http://hdl.handle.net/2122/8685 Title: Studio di fattibilità per il monitoraggio delle deformazioni del fondo marino tramite GPS su una meda elastica (Golfo di Pozzuoli – Campi Flegrei) Authors: De Martino, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Guardato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Tammaro, U.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Iannaccone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia Abstract: The continuous measurement of ground deformations is an important contribution to the monitoring of volcanic areas. When the volcano is totally or partially submerged, the traditional geodetic methods cannot be applied and the measures of seafloor deformation are extremely difficult and expensive. This paper describes the installation of a continuous GPS station on an elastic beacon. The measurements were conducted in the Campi Flegrei Caldera (Gulf of Pozzuoli, Naples), whose vertical displacements are related to the bradyseismic phenomenon. Experimental observations show that it’s possible to monitor vertical displacement of seafloor with a resolution of a few centimeters, also taking into account for measurement errors (due to weather and sea conditions acting on the elastic beacon). This non expensive technique is relevant at Campi Flegrei area, because it extends the ground deformation monitoring at sea, contributing to a better modeling of the deformation field. 2011-12-31T23:00:00Z 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/2122/8669 Title: Curie isotherm depth from aeromagnetic data constraining shallow heat source depths in the central Aeolian Ridge (Southern Tyrrhenian Sea, Italy) Authors: De Ritis, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Ravat, D.; Department of Earth and Environmental Sciences, University of Kentucky; Ventura, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Chiappini, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: The Salina, Lipari, and Vulcano volcanic ridge and the surrounding sea sectors (Aeolian Archipelago, Southern Tyrrhenian Sea, Italy) are characterized by vents responsible for a recent (<40 ka—1889/1890 AD) effusive and explosive subareal activity and repeated, 56 to 7 ka in age, submarine explosive eruptions from source areas located between Lipari and Vulcano. A spectral depth estimation of the magnetic bottom using a fractal method on aeromagnetic data from Vulcano, Lipari, and Salina volcanic ridge allows us to constrain the Curie isotherm depth. The elevated portion of the isotherm is between 2 and 3 km below Salina and Vulcano and about 1 km below Lipari. The Curie depth results in the context of other geological and geophysical evidence suggest that the rise of the Curie isotherm is mainly due to the occurrence of shallow heat sources such as magma ponds and associated hydrothermal systems. The short-wavelength magnetic anomaly field reflects magnetic contrasts from highly magnetized volcanic bodies, low-magnetization sediments, and hydrothermally altered rocks. Borehole temperature data verify the Curie temperature derived from the magnetic methods on the island of Vulcano.We conclude that the whole Vulcano, Lipari, and Salina volcanic ridge is active and should be monitored. 2013-03-19T23:00:00Z http://hdl.handle.net/2122/8648 Title: Understanding earthquakes: The key role of radar images Authors: Atzori, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia Abstract: The investigation of the fault rupture underlying earthquakes greatly improved thanks to the spread of radar images. Following pioneer applications in the eighties, Interferometry from Synthetic Aperture Radar (InSAR) gained a prominent role in geodesy. Its capability to measure millimetric deformations for wide areas and the increased data availability from the early nineties, made InSAR a diffused and accepted analysis tool in tectonics, though several factors contribute to reduce the data quality. With the introduction of analytical or numerical modeling, InSAR maps are used to infer the source of an earthquake by means of data inversion. Newly developed algorithms, known as InSAR time-series, allowed to further improve the data accuracy and completeness, strengthening the InSAR contribution even in the study of the inter- and post-seismic phase. In this work we describe the rationale at the base of the whole processing, showing its application to the New Zealand 2010-2011 seismic sequence. 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8632 Title: Preliminary investigation on soil CO2 and soil CH4 effluxes from a geothermal area near Palagonia (Sicily, Italy) Authors: Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Bonfanti, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Carapezza, M. L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Pagliuca, N.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Quattrocchi, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Ricci, T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Sciarra, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Spampinato, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia Abstract: The central part of eastern Sicily is characterized by several areas of strong crustal degassing. These gases are mostly carbon dioxide and methane and are particularly concentrated in some focused emissions (gas vents, mud volcanoes) or as diffuse degassing along major faults. In this study, the extent and orientation of soil CO2 and soil CH4 effluxes were investigated on a wide area (about 40 km2) located about 50 km southwest of Mt. Etna (Fig. 1). From a structural point of view, this area lays on a typical foredeep - foreland system that marks the boundary between the southern part of the Eurasian plate and the northern part of the African plate in the central Mediterranean. The situation was further complicated by the tectonic subsidence of the foredeep to the north of the northern Hyblean margin (YELLIN-DROR et alii, 1997; CARBONE et al., 1982) and the formation of a series of ENE-WSW oriented grabens and horsts, the Lentini Graben being the most important of these structures. This area was characterized by both submarine and subaerial volcanism until 1.7-2 Ma (BARBERI et alii, 1974; GRASSO et alii, 1983; GURENKO AND SCHMINCKE, 2002; SCHMINCKE et alii, 1997; TRUA et alii, 1997), and it was affected by strong seismicity in historical times. The surface geology consists of recent alluvial deposits and Plio-Pleistocene clays and sands interbedded with coeval basaltic lavas and pyroclastics of alkaline affinity (CARBONE et alii, 1987). Strong gas emissions in this area have been known since pre-Greek times, as reported by FERRARA (1805). PONTE (1919, 1934) showed that the gas that erupted through Naftìa Lake (located just southwest of the village of Palagonia, see Fig. 1) was pure carbon dioxide and calculated total emissions at about 80,000 t d-1. Today, the main gas emission is exploited for commercial use (Mofeta dei Palici plant, CO2 output estimated as about 250 t d-1, R. Romano pers. comm., 1998). The area is also characterized by several water well with warm (20-50 °C) water. Recent geochemical studies on this area (DE GREGORIO et alii, 2002; CARACAUSI et alii, 2003a, 2003b; GIAMMANCO et alii, 2007) showed that anomalous CO2 degassing has a hydrothermal or magmatic origin and it is linked to the dynamics of Mt. Etna’s plumbing system. 2012-08-31T22:00:00Z http://hdl.handle.net/2122/8619 Title: Quasi-synchronous multi-parameter anomalies associated with the 2010–2011 New Zealand earthquake sequence Authors: Qin, K.; College of Geosciences and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, China; Wu, L. X.; Academy of Disaster Reduction and Emergency Management, Ministry of Civil Affairs/Ministry of Education of P.R. China (Beijing Normal University), Beijing, China; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Meng, J.; College of Geosciences and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, China; Ma, W. Y.; College of Geosciences and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, China; Cianchini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: Positive thermal anomalies about one month before the 3 September 2010 Mw Combining double low line 7.1 New Zealand earthquake and " coincidental" quasi-synchronous fluctuations of GPS displacement were reported. Whether there were similar phenomena associated with the aftershocks? To answer it, the following was investigated: multiple parameters including surface and near-surface air temperature, surface latent heat flux, GPS displacement and soil moisture, using a long-term statistical analysis method. We found that local thermal and deformation anomalies appeared quasi-synchronously in three particular tectonic zones, not only about one month before the mainshock, but also tens of days before the 21 February 2011 Mw Combining double low line 6.3 aftershock, and that the time series of soil moisture on the epicenter pixel had obvious peaks on most of the anomalous days. Based on local tectonic geology, hydrology and meteorology, the particular lithosphere-coversphere-atmosphere coupling mode is interpreted and four mechanisms (magmatic-hydrothermal fluids upwelling, soil moisture increasing, underground pore gases leaking, and positive holes activating and recombining) are discussed. 2012-04-15T22:00:00Z http://hdl.handle.net/2122/8617 Title: MECHANISMS AND RELATIONSHIP TO SOIL MOISTURE OF SURFACE LATENT HEAT FLUX ANOMALY BEFORE INLAND EARTHQUAKES Authors: Qin, K.; China University of Mining and Technology (Beijing), Beijing, 10083; Wu, L.; Beijing Normal University, Beijing, 100875; Liu, S.; Northeastern University, Shenyang, 110004; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Cianchini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: The anomaly of SLHF, which is a key component of the Earth's energy balance and represents the heat flux from the Earth's surface to the atmosphere associated with evaporation or transpiration of water on the surface and subsequent condensation of water vapor in the troposphere, has been widely reported as a possible earthquake precursor. The causes are generally attributed to the increase in infrared thermal (IR) temperature and the air ionization produced by increased emanation of radon from the Earth's crust. In this paper, the theoretical analysis and case study show that there is close relationship between soil moisture and SLHF anomalies. For inland earthquakes, the increase of soil moisture due to the rising of groundwater level will bring with higher potential evaporation, leading to the increase of latent heat flux. Further study with more accurate soil moisture product after the new satellite mission will help us to better understand the influence of soil moisture on SLHF variation and their relations with seismogenic process. 2012-07-21T22:00:00Z http://hdl.handle.net/2122/8616 Title: IMPORTANCE OF LITHOSPHERE-COVERSPHERE-ATMOSPHERE COUPLING TO EARTHQUAKE ANOMALY RECOGNITION Authors: Wu, L.; Beijing Normal University, Beijing, 100875, China; Qin, K.; China University of Mining and Technology (Beijing), Beijing, 10083, China; Liu, S.; Northeastern University, Shenyang, 110004, China; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Cianchini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: The GEOSS under construction is providing space-,aero-,ground/sea-based multiple observations on planet Earth for the seismogenic process monitoring and earthquake precaution. The stress enhancement and energy accumulation in seismic activity area change locally the physical parameters of lithosphere with the developing of a series of effects that can comprise most of the following ones: initial cracks, the fracturing of rockmass, the changing of electromagnetic properties, the decreasing of dielectric constant, the re-activation of P-holes, the leaking of poregas, and the rise of water-level. The physical states of coversphere and atmosphere are to be affected due to the lithosphere-coversphere-atmosphere (LCA) coupling, and the signals from the underground, surface, and atmosphere to satellites are to be changed with parameter anomaly. We suggested that the LCA coupling is important for understanding GEOSS observations, especially for earthquake anomaly recognition (EAR). Using deviation-time-space-thermal (DTS-T) method for EAR, three recent major earthquakes (2009 Italy L'Aquila earthquake, 2010 China Yushu earthquake and 2010-2011 New Zealand earthquake sequence) are taken as typical cases for analysis to the multi-parameters anomalies, preceding the shocking, with quasi-synchronism and geoconsistency. The specific LCA coupling effects related with the earthquakes are also discussed in brief. 2012-07-21T22:00:00Z http://hdl.handle.net/2122/8615 Title: Preliminary analysis of surface temperature anomalies that preceded the two major Emilia 2012 earthquakes (Italy) Authors: Qin, K.; China University of Mining and Technology, College of Geosciences and Surveying Engineering, Beijing, China; Wu, L. X.; China University of Mining and Technology, School of Environment Science and Spatial Informatics, Xuzhou, China; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Cianchini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: In the 1980's, from an analysis of satellite images, Russian scientists reported on a short-term thermal infrared radiation enhancement that occurred before some medium-to-large earthquakes in central Asia [Gorny et al. 1988]. Since then, many researchers have been studying earthquake thermal anomalies with satellite remote sensing data [Qiang et al. 1991, Tronin 1996, Tramutoli et al. 2001, Ouzounov and Freund 2004, Saraf and Choudhury 2004, Aliano et al. 2008, Blackett et al. 2011]. Recently, abnormal surface latent heat flux [Dey and Singh 2003, Cervone et al. 2005, Qin et al. 2009, Qin et al. 2011, Qin et al. 2012], outgoing long-wave radiation [Ouzounov et al. 2007] and microwave radiation [Takashi and Tadashi 2010] have also been shown to precede earthquakes. To investigate the possible physical mechanisms of such satellite thermal anomalies, some studies conducted a series of detecting experiments on rock loaded to fracturing [Wu et al. 2000, Freund 2002, Wu et al. 2002, Wu et al. 2006a, Wu et al. 2006b, Freund et al. 2007], and some hypotheses have been proposed. These have included: leaking of pore-gas, and hence the resulting greenhouse effect [Qiang et al. 1995]; activating and recombining of p-holes during rock deformation [Freund 2002]; release of latent heat due to near-surface air ionization [Pulinets et al. 2006], and stress-induced thermal effects due to friction and fluids [Wu and Liu 2009]. According to the Istituto Nazionale di Geofisica e Vulcanologia (INGV; National Institute of Geophysics and Volcanology), two major earthquakes with almost the same large magnitudes struck northern Italy, on the Po Plain in the Emilia Region. The first hit on May 20, 2012, at 02:03 UTC, with ML 5.9 (44.89 °N, 11.23 °E; 6 km in depth), and the second on May 29, 2012, at 07:00 UTC, with ML 5.8 (44.85 °N, 11.09 °E; 10 km in depth). These caused a total of 27 deaths and widespread damage. In this study, the long-term temperature data from both satellite and ground (with greater emphasis on the satellite data) have been used to determine whether there were thermal anomalies associated with this Emilia 2012 seismic sequence. In particular, the next section will be dedicated to describing both the data and the method of analysis. In Section 3, we provide the more significant results, which we discuss in Section 4, together with the main conclusions. We acknowledge that this work cannot be exhaustive, as it will require more data and analyses. However, although further studies will be welcome, we are confident that we have done the best with the data at our disposal. 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8614 Title: Magnetic transfer function entropy and the 2009 Mw = 6.3 L’Aquila earthquake (Central Italy) Authors: Cianchini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Barraclough, D. R.; British Geological Survey, Edinburgh, UK; Wu, L. X.; Academy of Disaster Reduction and Emergency Management, Beijing Normal University, China; Qin, K.; China University of Mining and Technology, Beijing, China Abstract: With the aim of obtaining a deeper knowledge of the physical phenomena associated with the 2009 L’Aquila (Central Italy) seismic sequence, culminating with a Mw = 6.3 earthquake on 6 April 2009, and possibly of identifying some kind of earthquake-related magnetic or geoelectric anomaly, we analyse the geomagnetic field components measured at the magnetic observatory of L’Aquila and their variations in time. In particular, trends of magnetic transfer functions in the years 2006–2010 are inspected. They are calculated from the horizontal to vertical magnetic component ratio in the frequency domain, and are very sensitive to deep and lateral geoelectric characteristics of the measurement site. Entropy analysis, carried out from the transfer functions with the so called transfer function entropy, points out clear temporal burst regimes of a few distinct harmonics preceding the main shock of the seismic sequence. A possible explanation is that they could be related to deep fluid migrations and/or to variations in the micro-/meso-fracturing that affected significantly the conductivity (ordered/disordered) distribution in a large lithospheric volume under the seismogenic layer below L’Aquila area. This interpretation is also supported by the analysis of hypocentres depths before the main shock occurrence. 2012-07-22T22:00:00Z