http://hdl.handle.net/2122/201 2013-05-21T20:13:25Z 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/2122/7888 Title: Downhole Measurements in the AND-2A Borehole, ANDRILL Southern McMurdo Sound Project, Antarctica Authors: Wonik, T.; Leibniz Institute for Applied Geophysics, 30655 Hannover - Germany; Grelle, T.; Leibniz Institute for Applied Geophysics, 30655 Hannover - Germany; Handwerger, D.; TerraTek (Schlumberger), Salt Lake City, UT 84104 - USA; Jarrard, R. D.; Dept. of Geology and Geophysics, Univ. of Utah, Salt Lake City, UT 84112 - USA; McKee, A.; Raytheon Polar Services Corporation, Centennial, CO 80112-3938 - USA; Patterson, T.; Montana Tech, 1300 West Park Street, Butte, MT 59701 - USA; Paulsen, T.; Dept. of Geology, Univ. of Wisconsin at Oshkosh, Oshkosh, WI 54901-8649 - USA; Pierdominici, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Schmitt, D. R.; Inst. for Geophysical Research, Dept. of Physics, Univ. of Alberta, Edmonton, Alberta, T6G 2G7 - Canada; Schröder, H.; Leibniz Institute for Applied Geophysics, 30655 Hannover - Germany; Speece, M.; Montana Tech, 1300 West Park Street, Butte, MT 59701 - USA; Wilson, T.; School of Earth Sciences, The Ohio State University, Columbus, OH 43210-1522 - USA; the ANDRIL-SMS Science Team; http://andrill.org/projects/sms/team.html Abstract: Under the framework of the ANDRILL Southern McMurdo Sound (SMS) Project successful downhole experiments were conducted in the 1138.54 metre (m)-deep AND-2A borehole. Wireline logs successfully recorded were: magnetic susceptibility, spectral gamma ray, sonic velocity, borehole televiewer, neutron porosity, density, calliper, geochemistry, temperature and dipmeter. A resistivity tool and its backup both failed to operate, thus resistivity data were not collected. Due to hole conditions, logs were collected in several passes from the total depth at ~1138 metres below sea floor (mbsf) to ~230 mbsf, except for some intervals that were either inaccessible due to bridging or were shielded by the drill string. Furthermore, a Vertical Seismic Profile (VSP) was created from ~1000 mbsf up to the sea floor. The first hydraulic fracturing stress measurements in Antarctica were conducted in the interval 1000-1138 mbsf. This extensive data set will allow the SMS Science Team to reach some of the ambitious objectives of the SMS Project. Valuable contributions can be expected for the following topics: cyclicity and climate change, heat flux and fluid flow, seismic stratigraphy in the Victoria Land Basin, and structure and state of the modern crustal stress field. 2008-12-31T23:00:00Z http://hdl.handle.net/2122/7884 Title: Borehole breakout analysis: results from the AND-2A Well Authors: Montone, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Pierdominici, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Jarrard, R.D.; University of Utah, Salt Lake City; Wilson, T.; School of Earth Sciences, Ohio State University, 125 S. Oval Mall, Columbus, OH 43210 - USA; Paulsen, T.; University of Wisconsin – Oshkosh,; Wonik, T.; Inst. für Geowissen. Gemein., Hannover, Germany; Handwerger, D.; TerraTek, A Schlumberger Co., Salt Lake City Abstract: To define the present-day stress field in the upper crust and to understand the recent tectonic activity in Antarctica, a study of breakout measurements along AND-2A well was performed. The borehole breakout is an important indicator of horizontal stress orientation and occurs when the stresses around the borehole exceed that required to cause compressive failure of the borehole wall (Bell and Gough, 1979; Zoback et al., 1985, Bell, 1990). The enlargement of the wellbore is caused by the development of intersecting conjugate shear planes that cause pieces of the borehole wall to spall off. Around a vertical borehole, stress concentration is greatest in the direction of the minimum horizontal stress (Shmin), hence, the long axes of borehole breakouts are oriented approximately perpendicular to the maximum horizontal stress orientation (SHmax). The orientation of breakouts along the AND-2A well was measured using acoustic (BHTV) and mechanical (Four-Arm Caliper) tools. Borehole televiewer (BHTV) provides an acoustic "image" of the borehole wall (360 degree coverage) and gives detailed information for investigation of fractures and stress analysis. The four-arm caliper is the oldest technique for borehole breakout identification and it is included in routine dipmeter logs. A quality value has been assigned to the well results in agreement with the World Stress Map quality ranking scheme (Zoback, 1992; Heidback et al., 2010) based mainly on the number, accuracy, and length of breakout measurements. The result is presented as rose diagram of the breakout directions where the length of each peak is proportional to the frequency and the width to the variance of its gaussian curve. We have analyzed the following curves to recognize the breakout: the azimuth of Pad 1 (P1az), the drift azimuth (HAZI), the two calipers with respect to the bit size (BZ) curve and the curve relative to the deviation of the well. The AND-2A Four-Arm Caliper data cover a depth interval between 637 down to 997 mbsl, that corresponds to 360 m of logged interval. We have distinguished breakouts and some washouts only in the interval from 753 to 825 mbsl. From borehole televiewer images, we have data from 398 mbsl down to 1136 mbsl. The BHTV worked well showing a lot of interesting features such as many bedding, lamination and fractures (natural and induced) but poor breakouts. The rare breakouts have also a small size (called protobreakouts) but they are consistent with induced features. Considering the breakout result from caliper and BHTV, the AND-2A borehole is unfortunately classified as D quality. This means that to obtain a reliable active stress field of the area it is necessary to compare this result with other available data. 2009-12-31T23:00:00Z http://hdl.handle.net/2122/7882 Title: Fracture Logging of the AND-2A Core, ANDRILL Southern McMurdo Sound Project, Antarctica Authors: Paulsen, T.; Department of Geology, University of Wisconsin-Oshkosh, Oshkosh, WI 54901 - USA; Millan, C.; School of Earth Sciences, Ohio State University, 125 S. Oval Mall, Columbus, OH 43210 - USA; Pierdominici, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Wilson, T.; School of Earth Sciences, Ohio State University, 125 S. Oval Mall, Columbus, OH 43210 - USA; Drew, S.; School of Earth Sciences, Ohio State University, 125 S. Oval Mall, Columbus, OH 43210 - USA; ANDRIL-SMS Science Team; http://andrill.org/projects/sms/team.html Abstract: Fractures in AND-2A drillcore were documented in this study. Over 4100 fractures of all types were logged. A population of 510 steeply-dipping, petal, petal-centreline and core-edge induced fractures is present, reaching a maximum density of c. 10 fractures/metre. Subhorizontal induced extension fractures are also abundant. There are 1008 natural fractures in the core, including faults, brecciated zones, veins and sedimentary intrusions. Kinematic indicators document dominant normal faulting, although reverse faults are also present. The natural fractures occur in strata ranging in age from the Miocene to the Plio-Pleistocene. 2008-12-31T23:00:00Z http://hdl.handle.net/2122/7852 Title: Seismic Source Quantitative Parameters Retrieval From InSAR Data and Neural Networks Authors: Stramondo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Del Frate, F.; Picchiani, M.; Schiavon, G. Abstract: The basic idea of this paper relies on the concurrent exploitation of the capabilities of neural networks (NNs) and SAR interferometry (InSAR) for the characterization of a seismic source and the estimation of its geometric parameters. When a moderate-to-strong earthquake occurs, we can apply the InSAR technique to compute a differential interferogram. The earthquake is generated by an active seismogenic fault having its own specific geometry. The corresponding differential interferogram contains, in principle, information concerning the geometry of the seismic source that the earthquake comes from. To perform the inversion operation, a novel approach based on NNs is considered. This requires the generation of a statistically significant number of synthetic interferograms necessary for the network training phase. Each of them corresponds to a different combination of fault geometric parameters. After the training, the network is ready to perform, in real time, the inversion on new differential interferograms. This paper illustrates such a methodology and its validation on a set of experimental data. 2010-12-31T23:00:00Z http://hdl.handle.net/2122/7533 Title: Microzonazione sismica di un centro abitato di piccole dimensioni: il caso studio di Sant’Agata Fossili (AL) Authors: Podestà, Stefano; DICAT – Università di Genova; Conte, Riccardo; Regione Piemonte-Direzione Opere Pubbliche, Difesa del suolo ed Economia Montana e Foreste, Torino; Compagnoni, Massimo; DIS-Politecnico di Milano; Di Capua, Giuseppe; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia; Di Giulio, Giuseppe; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Marchetti, Marco; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Milana, Giuliano; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Passalacqua, Roberto; DICAT – Università di Genova; Peppoloni, Silvia; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia; Pergalani, Floriana; DIS-Politecnico di Milano Editors: Mezzina, Mauro; Politecnico di Bari Abstract: In questo lavoro sono descritte le attività svolte nell’ambito del Progetto Europeo Strategico RISKNAT riguardanti l’analisi di microzonazione di Sant’Agata Fossili (AL). Sono in particolare descritte tutte le indagini ed analisi numeriche condotte al fine di ottenere una microzonazione sismica di livello 3 secondo quanto previsto nelle recenti linee guida nazionali degli. Al fine inoltre di valutare le ricadute di tipo applicativo di una corretta microzonazione sismica del territorio, sono state realizzate delle simulazioni di scenario adottando come riferimento gli spettri di risposta ottenuti dall’analisi di microzonazione. Le valutazioni di scenario ottenute sono state infine confrontate con le previsioni di scenario realizzabili a priori sulla base dell’adozione degli spettri di risposta definiti nelle Norme Tecniche per le Costruzioni. 2011-09-17T22:00:00Z http://hdl.handle.net/2122/7422 Title: Secondary hydrothermal minerals in buried rocks at the campi flegrei caldera, Italy: a possible tool to understand the rock-physics and to assess the state of the volcanic system Authors: Mormone, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Tramelli, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Di Vito, M. A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Piochi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Troise, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; De Natale, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia Abstract: The distribution of the alteration assemblages and the related physico-chemical changes induced in the rocks with depth, may provide useful information on the state of the system. Drillholes are the only way to define hydrothermal alteration depth-profiles in variable geological contexts. Deep drillings exploiting programs were conducted since the 1970’s by the Agip-Enel Joint Venture in the Quaternary Campi Flegrei caldera (southern Italy), where a geothermal system has been active since at least historical times. New macroscopic and microscopic investigations were performed on selected samples made available by Agip in order to: 1) define the precursor lithology, 2) describe the relationships among texture, mineralogy and depth of the studied core samples and 3) examine the character of the secondary minerals and their distribution with depth and temperature. The new data are integrated with physical properties and elastic parameters of cored rocks, as well as structural information and field data, all available from the physical, seismological, geodetical and volcanological literature. The depth-related multi-parameters profiles provide evidence on the different behavior of the buried rocks beneath the Licola 1, Mofete and San Vito 1 areas, sited in three structurally different sectors of the caldera. The features of the hydrothermally altered rocks are a key to interpret the heterogeneities of the Campi Flegrei substratum, as deduced by velocity, attenuation and scattering P- and S- waves tomography. The time and space distribution of both the eruptive vents and the extruded magma volumes are consistent with the results of our analysis. Therefore, we interpret the observed Campi Flegrei geothermal system as a response to the distribution of volcanic activity in two structurally distinct sectors of the caldera. The central-eastern sector, where the San Vito 1 well was drilled, represents the preferential pathways for both gas escape and magma ascent at least since 8 kyrs, in contrast with the other sites of the caldera where eruptions occurred with minor frequency and magnitude. 2011-12-12T23:00:00Z