1,721,049 research outputs found
Deep structures of central Apennines from 3D and 2D gravity modelling along CROP11 seismic profile
No full textWe use gravity data to reconstruct the deep structure of central Ital
Gravity modelling of central Apennines deep structures along CROP11 seismic profile
No full textgravity data inversion and interpretation in terms of deep structure
Integrating geologic fault data into tsunami hazard studies
No full textWe present the realization of a fault-source data set designed to become the starting point in regional-scale tsunami hazard studies. Our approach focuses on the parametric fault characterization in terms of geometry, kinematics, and assessment of activity rates, and includes a systematic classification in six justification levels of epistemic uncertainty related with the existence and behaviour of fault sources. We set up a case study in the central Mediterranean Sea, an area at the intersection of the European, African, and Aegean plates, characterized by a complex and debated tectonic structure and where several tsunamis occurred in the past. Using tsunami scenarios of maximum wave height due to crustal earthquakes (Mw7) and subduction earthquakes (Mw7 and Mw8), we illustrate first-order consequences of critical choices in addressing the seismogenic and tsunamigenic potentials of fault sources. Although tsunamis generated by Mw8 earthquakes predictably affect the entire basin, the impact of tsunamis generated by Mw7 earthquakes on either crustal or subduction fault sources can still be strong at many locales. Such scenarios show how the relative location/orientation of faults with respect to target coastlines coupled with bathymetric features suggest avoiding the preselection of fault sources without addressing their possible impact onto hazard analysis results. © 2013 Author(s)
2D gravity modelling along the CROP11 seismic profile
No full text2-D gravity to reconstruct the deep structures along central Ital
Deliverable # 3.01.3 Seismogenic sources in the studied key areas (contributing to populate the DISS)
No full textThis deliverable consists of 12 new composite and 3 individual seismogenic sources in the Dinarides. They are full-fledged records to be entered in the DISS following the database structure illustrated in Basili et al. (2008) and documentation requirements set forth by RU3.12 in this project (Basili et al., 2009). The area covered by these new records is a work in progress towards filling in the information gap about the active tectonic structures on the eastern side of the Adriatic Sea, mainly located along the coast and off-shore areas of Croatia. This new dataset was made available to UR 3.12 for updating the DISS and to other project
partners. It will also be part of the new version of DISS after thorough revision and validation on the DISS website (http://diss.rm.ingv.it/diss).Agreement INGV-DPC 2007-2009
Project S1: Analysis of the seismic potential in Italy for the evaluation of the seismic hazardPublished3.2. Tettonica attiva4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionaleope
PON-MASSIMO. Report sulle attività di ricerca e sviluppo. Analisi delle sorgenti sismogenetiche - I semestre
No full textLa conoscenza dell’ubicazione e delle caratteristiche geometriche e cinematiche delle sorgenti
sismogenetiche costituisce il dato di partenza fondamentale per la valutazione della pericolosità sismica sia
per meglio finalizzare ulteriori indagini di dettaglio, sia per l’elaborazione di scenari deterministici di
scuotimento.
Avvalendosi dell’esperienza acquisita nella compilazione del Database of Individual Seismogenic Sources
(DISS), sono state pertanto effettuati la revisione e l’aggiornamento delle sorgenti sismogenetiche che
maggiormente interessano le città di Cosenza, Vibo Valentia e Reggio Calabria.
Inoltre, in molte aree la magnitudo massima possibile (Mf) può essere maggiore di quella riportata nei
cataloghi storici (Mh). Al fine di individuare le aree dove il superamento della magnitudo osservata finora è
più probabile sono stati utilizzati modelli di distrubuzione frequenza/magnitudo bilanciati con il moment rate
tettonico per definire quanto frequentemente la magnitudo osservata può essere superata di un valore ε
assegnato.
Le attività finora completate non presentavano rischi, per cui non è possibile una valutazione dell’efficacia
delle politiche di mitigazione.
L’elaborazione degli scenari di scuotimento verrà effettuata in seguito.PON 01/02710 MASSIMO, MIUR, PON Ricerca e competitività 2007-2013Unpublishedreserve
2D gravity modelling along the CROP11 seismic profile
No full textThe purpose of this work is to present a gravity reconstruction of the deepest portion
of the CROP 11 seismic line. The 2D gravity modelling is constrained by DSS data
and by deep reflection seismic data obtained along the CROP 11 line. The role of the
regional gravity anomaly trend of Central Italy as an independent constraint for the
geological interpretation of the seismic line is also highlighted. The main gravity low
(Fucino Plain) in the area is compensated by the combined effect of a regional deepening
of both the Moho and the top of the crystalline basement, while the gravity low,
located east towards the Maiella Mt., seems to originate between a 4 and 10 km depth.
A lower density can be assigned to the western portion of the mantle with respect to
the eastern side. The westernmost part of the upper crust in the model also shows a
slightly lower density. The crystalline basement is not likely to be heavily involved in
the deformation of the chain; ramp-and-flat deformations are present down to a depth
of 20 km, i.e. the “highly reflective body” on the western side of the profile, which
does not have a marked gravity imprint and should be due to relatively “light” sedimentary
units.Published447-454ope
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Probabilistic hazard for seismically induced tsunamis: Accuracy and feasibility of inundation maps
No full textProbabilistic tsunami hazard analysis (PTHA) relies on computationally demanding numerical simulations of tsunami generation, propagation, and non-linear inundation on high-resolution topo-bathymetric models. Here we focus on tsunamis generated by co-seismic sea floor displacement, that is, on Seismic PTHA (SPTHA). A very large number of tsunami simulations are typically needed to incorporate in SPTHA the full expected variability of seismic sources (the aleatory uncertainty). We propose an approach for reducing their number. To this end, we (i) introduce a simplified event tree to achieve an effective and consistent exploration of the seismic source parameter space; (ii) use the computationally inexpensive linear approximation for tsunami propagation to construct a preliminary SPTHA that calculates the probability of maximum offshore tsunami wave height (HMax) at a given target site; (iii) apply a two-stage filtering procedure to these 'linear' SPTHA results, for selecting a reduced set of sources and (iv) calculate 'non-linear' probabilistic inundation maps at the target site, using only the selected sources. We find that the selection of the important sources needed for approximating probabilistic inundation maps can be obtained based on the offshore HMax values only. The filtering procedure is semi-automatic and can be easily repeated for any target sites. We describe and test the performances of our approach with a case study in theMediterranean that considers potential subduction earthquakes on a section of the Hellenic Arc, three target sites on the coast of eastern Sicily and one site on the coast of southern Crete. The comparison between the filtered SPTHA results and those obtained for the full set of sources indicates that our approach allows for a 75-80 per cent reduction of the number of the numerical simulations needed, while preserving the accuracy of probabilistic inundation maps to a reasonable degree
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