Bollettino Di Geofisica Teorica Ed Applicata最新文献

{"title":"One year of RST based satellite thermal monitoring over two Italian seismic areas","authors":"Tramutoli, R. Corrado, C. Filizzola, N. Genzano, M. Lisi, R. Paciello, N. Pergola","doi":"10.4430/BGTA0150","DOIUrl":"https://doi.org/10.4430/BGTA0150","url":null,"abstract":"In this study, Earth’s emitted Thermal InfraRed (TIR) radiation measured from geostationary satellite sensors has been analyzed by using an original data analysis approach in order to evaluate possible space-time correlation with earthquakes (M≥4.0) occurrence. A clear definition of SSTA (Significant Sequence of Thermal Anomaly) concept is given and correlation rules are established in order to evaluate the potential of SSTAs among the parameters to be included in a pre-operational system for timeDependent Assessment of Seismic Hazard (t-DASH). On the considered time period (July 2012 June 2013) and testing areas (Italian southern Apennines and Po Plain) a false positive rate lesser than 33% has been obtained. Notwithstanding a missing rate up to 67% (mostly because of the presence of clouds preventing the continuity of observations), as confirmed by other independent studies performed on longer period of time and different geographic areas, seems to strongly support the inclusion of SSTAs [identified by the RST (Robust Satellite Technique) methodology] among the parameters whose continuous monitoring and integration with all the other relevant information available, could strongly improve our present capabilities to dynamically assess seismic hazard in a pre-operational context.","PeriodicalId":50728,"journal":{"name":"Bollettino Di Geofisica Teorica Ed Applicata","volume":"56 1","pages":"275-294"},"PeriodicalIF":1.2,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70797649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Peloponnese continental margin from Zakynthos Island to Pylos: morphology and recent sedimentary processes","authors":"J. Mascle, Laurent Caméra, N. Wardell, D. Accettella","doi":"10.4430/BGTA0092","DOIUrl":"https://doi.org/10.4430/BGTA0092","url":null,"abstract":"Funded by the EEC Sixth Framework Program, the SEAHELLARC project was \u0000aimed to evaluate, and better understand the causes, of the various natural geohazards \u0000(chiefly earthquakes and tsunamis), which frequently affect the western Peloponnese \u0000area and particularly its coastal domain; this region is one of the most seismically \u0000active of Greece and therefore of the Mediterranean Sea. Based on a set of new \u0000geophysical data, such as detailed swath bathymetry and high-resolution sub-bottom \u0000Chirp, we have distinguished and studied four contrasted domains along this area of \u0000the Peloponnese active continental margin underlined by intense crustal seismicity \u0000and marked by very contrasted and often sharp continental slopes; from east to \u0000west these are: (1) an area including the continental shelf and the upper slope; there \u0000sedimentary overload and destabilizations, syn-sedimentary faults, mass transport \u0000deposits and active sedimentary by-pass mechanisms are the main risk factors. (2) The \u0000middle to lower continental slopes, is mainly expressed by two, N-S trending, fault- \u0000related, depressions, where active deformations, well recorded by actual tilting of the \u0000sedimentary blanket, occur. (3) West of this deep structural depressions exists a poorly \u0000sedimented ridge area (from which merges the small Strophades Islands) also showing \u0000N-S and E-W trending lineaments resulting in a dense network of fractures and scarps \u0000and leading too a particularly complex sub-marine morphology; this area, together \u0000with the westernmost deep domain (4), which bounds the continental margin, clearly \u0000records the effects of significant active tectonic. Our studies of the shallow and recent \u0000sedimentary cover of the continental margin off western Peloponnese, confirm that this \u0000active margin segment is an area where geohazards can be expected. In addition to fault \u0000ruptures, generated at depth by the specific tectonic framework, sedimentary collapses, \u0000particularly along the shelf break nearby Cape Katakolo, may trigger significant local \u0000tsunamis, which may in turn induce strong damages all along the nearby coasts up to \u0000the town of Pylos.","PeriodicalId":50728,"journal":{"name":"Bollettino Di Geofisica Teorica Ed Applicata","volume":"55 1","pages":"325-342"},"PeriodicalIF":1.2,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4430/BGTA0092","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70797430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toward validation of simulated accelerograms via prediction equations for nonlinear SDOF response","authors":"F. Luca, G. Ameri, I. Iervolino, F. Pacor, D. Bindi","doi":"10.4430/BGTA0114","DOIUrl":"https://doi.org/10.4430/BGTA0114","url":null,"abstract":"Seismic structural risk analysis of critical facilities may require nonlinear dynamic analysis for which record selection is one of the key issues. Notwithstanding the increasing availability of database of strong-motion records, it may be hard to find accelerograms that fit a specific scenario (e.g., in terms of magnitude and distance) resulting from hazard assessment at the site of interest. A possible, alternative, approach can be the use of artificial and/or simulated ground motion in lieu of real records. Their employment requires systematic engineering validation in terms of structural response and/or seismic risk. Prediction equations for peak and cyclic inelastic single degree of freedom systems’ response, based on Italian accelerometric data, are discussed in this study as a possible benchmark, alongside real record counterparts, for the validation of synthetic records. Even if multiple events would be in principle required, an extremely preliminary validation is carried out considering only four simulated records of the 1980 Irpinia (Southern Italy) Mw 6.9 earthquake. Simulated records are obtained through a broadband hybrid integral-composite technique. Results show how this simulation method may lead to generally acceptable results. It is also emphasized how this kind of validation may provide additional results with respect to classical signal-to-signal comparison of real and simulated records.","PeriodicalId":50728,"journal":{"name":"Bollettino Di Geofisica Teorica Ed Applicata","volume":"55 1","pages":"85-101"},"PeriodicalIF":1.2,"publicationDate":"2014-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4430/BGTA0114","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70797826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic analysis of an isolated and a non-isolated light-frame timber building using artificial and natural accelerograms","authors":"L. Sancin, G. Rinaldin, M. Fragiacomo, C. Amadio","doi":"10.4430/BGTA0093","DOIUrl":"https://doi.org/10.4430/BGTA0093","url":null,"abstract":"Light-frame construction is used extensively for low and medium rise timber buildings. These buildings are light-weight and have a high dissipative capacity which, on the other hand, may imply significant structural and non-structural damage at the end of a high intensity earthquake ground motion, leading to potentially significant economic losses. Passive base isolation is by far the most effective way to reduce the effect of an earthquake on a structure. In this paper, the use of Friction Pendulum System isolators is investigated for a three-storey light-frame timber building. Two designs of the same building, with and without passive base isolation, were carried out according to Eurocodes 5 and 8 and the Italian technical regulation for construction. The buildings were then analysed using linear and non-linear methods. The seismic performance and cost of both solutions are compared, demonstrating the convenience of using passive base isolation.","PeriodicalId":50728,"journal":{"name":"Bollettino Di Geofisica Teorica Ed Applicata","volume":"55 1","pages":"103-118"},"PeriodicalIF":1.2,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4430/BGTA0093","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70797490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early instrumental seismicity recorded in the eastern Alps","authors":"D. Sandron, G. Renner, A. Rebez, D. Slejko","doi":"10.4430/BGTA0118","DOIUrl":"https://doi.org/10.4430/BGTA0118","url":null,"abstract":"Three hundred and seventy-five earthquakes recorded by the Trieste station in the eastern Alps in the early instrumental period, i.e., before the occurrence of the destructive event of May 6, 1976, have been located after painstaking gathering of seismograms and bulletins. Analysis of the statistical parameters of the locations, together with comparisons with other instrumental and macroseismic locations, have allowed us to assess the quality of the results obtained, taking into account the often limited nature of the data. Using a process of digitization and the study of seismograms, focal parameters, particularly the magnitude Mw, have been recovered for three earthquakes of the 1950s and 1960s.","PeriodicalId":50728,"journal":{"name":"Bollettino Di Geofisica Teorica Ed Applicata","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4430/BGTA0118","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70797735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The revision of the 30 October 1901 earthquake, west of Lake Garda (northern Italy)","authors":"V. Pessina, A. Tertulliani, R. Camassi, A. Rossi, G. Scardia","doi":"10.4430/BGTA0083","DOIUrl":"https://doi.org/10.4430/BGTA0083","url":null,"abstract":"On November 24, 2004 an earthquake (Mw= 5.0) struck the west side of Lake Garda (northern Italy), producing moderate but widespread damage. It provided the opportunity of reviewing the seismicity of all the area over the past two centuries, whose former most significant event is the October 30, 1901 earthquake (Mw= 5.5), while other minor but damaging events are the January 5, 1892 (Mw=5.0) and November 16, 1898 (Mw=4.6) earthquakes. On the reviewing we found common similarities in ground shaking distribution as recurrent damaged spots, amplification zones due to local site condition or energy radiation. We believe that these findings are suitable to provide information for provisional purposes in low hazard level area hampered by the lack of knowledge about the seismic sources. New data are provided both in MCS scale and EMS. The sensitivity of a source parameters estimation technique was evaluated for the major event.","PeriodicalId":50728,"journal":{"name":"Bollettino Di Geofisica Teorica Ed Applicata","volume":"54 1","pages":"77-110"},"PeriodicalIF":1.2,"publicationDate":"2013-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70797357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crustal fracturing and presence of fluid as revealed by seismic anisotropy: case histories from seismogenic areas in the Apennines (Italy)","authors":"M. Pastori, D. Piccinini, L. Valoroso, A. Wuestefeld, L. Zaccarelli, F. Bianco, J. Kendall, D. Bucci, L. Margheriti, M. Barchi, J. Kendall","doi":"10.4430/BGTA0047","DOIUrl":"https://doi.org/10.4430/BGTA0047","url":null,"abstract":"An automatic analysis code, Anisomat+, was developed, tested and improved to calculate anisotropic parameters: fast polarization direction and delay time. Anisomat+ was applied on data coming from three zones of the Apennines in Italy. For each area, anisotropic parameters have been interpreted to determine the fracture and stress field taking into account the geological and structural settings. It was recognized that the averages of fast directions are NW-SE–oriented at all sites, in agreement with the orientation of maximum horizontal stress as well as with the strike of the main fault structures. The mean values of normalized delay time range from 0.005 s/km to 0.007 s/km and to 0.009 s/km, respectively for L'Aquila region, Alto Tiberina Fault area and Val d'Agri basin, suggesting a 3-4% of crustal anisotropy. Moreover, for each area, the spatial distribution of anisotropic parameters is examined, and for L’Aquila 2009 seismic sequence also temporal distribution is discussed.","PeriodicalId":50728,"journal":{"name":"Bollettino Di Geofisica Teorica Ed Applicata","volume":"111 1","pages":"417-433"},"PeriodicalIF":1.2,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4430/BGTA0047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70797024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupled seismogenic geohazards in alpine regions","authors":"D. Fäh, J. Moore, J. Burjánek, I. Iosifescu, L. Dalguer, F. Dupray, C. Michel, J. Woessner, A. Villiger, J. Laue, Iris Marschall, V. Gischig, S. Loew, A. Marin, Gabriela Gassner, Sonia Alvarez, W. Balderer, P. Kästli, D. Giardini, Cristina Iosifescu, L. Hurni, P. Lestuzzi, A. Karbassi, Cyrill Baumann, A. Geiger, A. Ferrari, L. Laloui, J. Clinton, N. Deichmann","doi":"10.4430/BGTA0048","DOIUrl":"https://doi.org/10.4430/BGTA0048","url":null,"abstract":"COupled seismogenic GEohazards in Alpine Regions (COGEAR) is an interdisciplinary natural hazard project investigating the hazard chain induced by earthquakes. It addresses tectonic processes and the related variability of seismicity in space and time, earthquake forecasting and short-term precursors, and strong ground motion as a result of source and complex path effects. We study non-linear wave propagation phenomena, liquefaction and triggering of landslides in soil and rock, as well as earthquake-induced snow avalanches. The Valais, and in particular parts of the Rhone, Visper, and Matter valleys have been selected as study areas. Tasks include detailed field investigations, development and application of numerical modeling techniques, assessment of the susceptibility to seismically induced effects, and installation of different monitoring systems to test and validate our models. These systems are for long-term operation and include a continuous GPS and seismic networks, a test installation for observing earthquake precursors, and a system to study site-effects and non-linear phenomena in two test areas (Visp, St. Niklaus / Randa). Risk-related aspects relevant for buildings and lifelines are also considered.","PeriodicalId":50728,"journal":{"name":"Bollettino Di Geofisica Teorica Ed Applicata","volume":"53 1","pages":"485-508"},"PeriodicalIF":1.2,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4430/BGTA0048","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70797180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A least-squares collocation procedure to merge local geoids with the aid of satellite-only gravity models: the Italian/Swiss geoids case study","authors":"M. Gilardoni, M. Reguzzoni, D. Sampietro","doi":"10.4430/BGTA0111","DOIUrl":"https://doi.org/10.4430/BGTA0111","url":null,"abstract":"Neighbouring countries often have national geoids that do not fit to each other, typically showing a discontinuity along the border. Among other effects, this discontinuity is mainly due to the different height datum, producing biased local geoids which can also have different accuracies and spatial resolutions. In some applications, for instance in case of international civil engineering works, a merging between two neighbouring geoids can be necessary. Obviously this procedure cannot be done by simply averaging overlapping areas completely disregarding biases. This paper deals with this problem in connection to the availability of data from satellite gravity missions. In contrast to terrestrial gravity anomalies, gravity and geoid models derived from satellite gravity missions, and in particular from GRACE and GOCE, do not suffer from those inconsistencies. These models in fact are not affected by local biases (local reference systems) since they do not make use of any ground gravity data or levelling. Basically this means that these models can provide the long wavelengths of the resulting merged geoid, in this way removing national biases or other systematic effects. On the other hand, the short wavelengths will directly come from a combination of the available local geoids. This article proposes a least-squares collocation procedure to merge local geoids with the help of these satellite-only gravity models. Even if the correct approach to produce a unique unbiased geoid is to start from the original terrestrial gravity data together with satellite data, the presented procedure can be helpful to merge already available local models. After a review of the mathematical formulation of the problem, the paper illustrates the case of the merging of the Italian and Swiss geoids, more specifically the Swiss CHGeo2004 and the Italian ITALGEO2005 pure gravimetric local models. A constant bias with respect to the GOCE reference (WGS84 ellipsoid) of about 100 cm for the Italian local geoid and of about 80 cm for the Swiss one have been estimated and removed. After that a unique geoid with an accuracy of few centimetres has been computed by collocation. A first application of this new geoid, named GISgeo2012 (GOCE, Italian and Swiss geoid) will be within the interreg project Helidem (HELvetia-Italy Digital Elevation Model) to create a new unified digital elevation model in orthometric height.","PeriodicalId":50728,"journal":{"name":"Bollettino Di Geofisica Teorica Ed Applicata","volume":"54 1","pages":"303-319"},"PeriodicalIF":1.2,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4430/BGTA0111","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70797543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of CO2-gas emission variations in the central Apennines (Italy) during the L'Aquila seismic sequence (March-April 2009)","authors":"P. Bonfanti, N. Genzano, J. Heinicke, F. Italiano, G. Martinelli, N. Pergola, L. Telesca, V. Tramutoli","doi":"10.4430/BGTA0043","DOIUrl":"https://doi.org/10.4430/BGTA0043","url":null,"abstract":"The occurrence of intense CO2 degassing processes generating hundreds of cold CO2rich gas emissions is typical of the central Apennines. In 2009, significant anomalies were detected coinciding with the L’Aquila seismic sequence as a consequence of a wide degassing process. Over the same time-span, space-time anomalies in Thermal InfraRed (TIR) satellite imagery possibly related to the increase of green-house gas (such as CO2, CH4, etc.) emission rates were detected in central Italy during the seismic swarm by a Robust Satellite Technique (RST) data analysis. A gas geochemical survey carried out in the L’Aquila area confirms the deep crustal origin of the anomalous gas emission detected by ground measurements. Anomalous fluid related signals were recorded some days before the mainshock coinciding with the most marked TIR anomalies independently detected by the RST analysis over 3 different types of satellite data. Anomalous gas emissions detected by ground measurements lasted some weeks, putting in evidence relationships with crustal deformative processes associated with the seismic sequence. Together with previous ground observations in the Umbria-Marche area, present ground and satellite TIR observations, are compatible with the hypothesis that a central Apennines area, much wider than the L’Aquila (March-April 2009) epicentral one, was actually affected by anomalous increases in CO2 release thus providing new tools to better understand the processes occurring behind a seismic shock.","PeriodicalId":50728,"journal":{"name":"Bollettino Di Geofisica Teorica Ed Applicata","volume":"66 1","pages":"147-168"},"PeriodicalIF":1.2,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4430/BGTA0043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70796941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}