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Scherbaum, F.
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- PublicationRestrictedStatistical analysis of the Central-Europe seismicity(2009-05-29)
; ; ; ;Faenza, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Hainzl, S.; GeoForschungsZentrum, Telegrafenberg, 14473 Potsdam, Germany ;Scherbaum, F.; Institute of Earth Sciences, University of Potsdam, Karl-Liebknecht Str. 24, 14476 Potsdam - Golm, Germany; ; The aim of this paper is to characterize the spatio-temporal distribution of Central-Europe seismicity. Specifically, by using a non-parametric statistical approach, the proportional hazard model, leading to an empirical estimation of the hazard function, we provide some constrains on the time behavior of earthquake generation mechanisms. The results indicate that the most conspic- uous characteristics of MW 4.0+ earthquakes is a temporal clustering lasting a couple of years. This suggests that the probability of occurrence increases immediately after a previous event. After a few years, the process becomes almost time independent. Furthermore, we investigate the cluster properties of the seismicity of Central-Europe, by comparing the obtained result with the one of synthetic catalogs generated by the epidemic type aftershock sequences (ETAS) model, which previously have been successfully applied for short term clustering. Our results indicate that the ETAS is not well suited to describe the seismicity as a whole, while it is able to capture the features of the short- term behaviour. Remarkably, similar results have been previously found for Italy using a higher magnitude threshold.158 20 - PublicationOpen AccessSeismic array analysis of Tornillo-like signals recorded in Tuscany(2006-11)
; ; ; ; ; ;Braun, T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Dahm, T.; Inst. f. Geophysik, Uni Hamburg ;Krüger, F.; Inst. f. Geowissenschaften, Uni Potsdam ;Ohrnberger, M.; Inst. f. Geowissenschaften, Uni Potsdam ;Scherbaum, F.; Inst. f. Geowissenschaften, Uni Potsdam; ; ; ; With the scientific purpose to monitor the micro-seismicity in the Central Apennines, we recently deployed in Eastern Tuscany (Casentino) a temporary 12 element seismic array, composed exclusively of 3-component seismometers. During the one month of registration we recorded an unexpected high rate of local micro-seismicity with up to 180 events per day.116 103 - PublicationOpen AccessAmbient vibration measurements in the Southern Rhine Graben close to Basle(2004)
; ; ; ; ; ;Köhler, A.; Institut für Geowissenschaften, Universität Potsdam, Germany ;Ohrnberger, M.; Institut für Geowissenschaften, Universität Potsdam, Germany ;Scherbaum, F.; Institut für Geowissenschaften, Universität Potsdam, Germany ;Stange, S.; Erdbebendienst des Landesamts für Geologie, Rohstoffe und Bergbau Baden-Württemberg (LGRB), Freiburg im Breisgau, Germany ;Kind, F.; Swiss Seismological Service, Eidgenössische Technische Hochschule Zürich, Hönggerberg, Zürich, Switzerland; ; ; ; This study presents results of ambient noise measurements from temporary single station and small-scale array deployments in the northeast of Basle. H/V spectral ratios were determined along various profiles crossing the eastern masterfault of the Rhine Rift Valley and the adjacent sedimentary rift fills. The fundamental H/V peak frequencies are decreasing along the profile towards the eastern direction being consistent with the dip of the tertiary sediments within the rift. Using existing empirical relationships between H/V frequency peaks and the depth of the dominant seismic contrast, derived on basis of the ?/4-resonance hypothesis and a power law depth dependence of the S-wave velocity, we obtain thicknesses of the rift fill from about 155 m in the west to 280 m in the east. This is in agreement with previous studies. The array analysis of the ambient noise wavefield yielded a stable dispersion relation consistent with Rayleigh wave propagation velocities. We conclude that a significant amount of surface waves is contained in the observed wavefield. The computed ellipticity for fundamental mode Rayleigh waves for the velocity depth models used for the estimation of the sediment thicknesses is in agreement with the observed H/V spectra over a large frequency band.226 203 - PublicationOpen AccessComparisons among the five ground-motion models developed using RESORCE for the prediction of response spectral accelerations due to earthquakes in Europe and the Middle East(2014-02)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Douglas, J.; BRGM, Orléans, France ;Akkar, S.; Middle East Technical University, Ankara, Turkey ;Ameri, G.; FUGRO-Geoter, Auriol, France. ;Bard, P.; ISTerre, Grenoble, France ;Bindi, D.; GFZ, Potsdam, Germany ;Bommer, J.; Imperial College London, United Kingdom ;Bora, S. S.; Inst. Erd- und Umweltwissesnschaften, Universitaet Potsdam, Germany ;Cotton, F.; ISTerre, Grenoble, France ;Derras, B.; ISTerre, Grenoble, France ;Hermkes, M.; Inst. Erd- und Umweltwissesnschaften, Universitaet Potsdam, Germany ;Kuehn, N. M.; Inst. Erd- und Umweltwissesnschaften, Universitaet Potsdam, Germany ;Luzi, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia ;Massa, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia ;Pacor, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia ;Riggelsen, C.; Inst. Erd- und Umweltwissesnschaften, Universitaet Potsdam, Germany ;Sandikkaya, M. A.; Middle East Technical University, Ankara, Turkey ;Scherbaum, F.; Inst. Erd- und Umweltwissesnschaften, Universitaet Potsdam, Germany ;Stafford, P.; Imperial College London, United Kingdom ;Traversa, P.; EDF, Aix en Provence, France; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; This article presents comparisons among the five ground-motion models described in other articles within this special issue, in terms of data selection criteria, characteristics of the models and predicted peak ground and response spectral accelerations. Comparisons are also made with predictions from the Next Generation Attenuation (NGA) models to which the models presented here have similarities (e.g. a common master database has been used) but also differences (e.g. some models in this issue are nonparametric). As a result of the differing data selection criteria and derivation techniques the predicted median ground motions show considerable differences (up to a factor of two for certain scenarios), particularly for magnitudes and distances close to or beyond the range of the available observations. The predicted influence of style-of-faulting shows much variation among models whereas site amplification factors are more similar, with peak amplification at around 1s. These differences are greater than those among predictions from the NGA models. The models for aleatory variability (sigma), however, are similar and suggest that ground-motion variability from this region is slightly higher than that predicted by the NGA models, based primarily on data from California and Taiwan.214 263 - PublicationRestrictedToward a ground-motion logic tree for probabilistic seismic hazard assessment in Europe(2012-02-22)
; ; ; ; ; ; ; ; ; ; ; ; ; ;Delavaud, E.; ISTerre, Université Joseph Fourier, CNRS, BP 53, 38041 Grenoble, France ;Cotton, F.; ISTerre, Université Joseph Fourier, CNRS, BP 53, 38041 Grenoble, France ;Akkar, S.; Earthquake Engineering Research Center, Department of Civil Engineering, METU, 06531 Ankara, Turkey ;Scherbaum, F.; Institute of Earth and Environmental Sciences, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Golm, Germany ;Danciu, L.; Swiss Seismological Service, Institute of Geophysics, ETH Zurich, Sonneggstrasse 5, NO, 8092 Zurich, Switzerland ;Beauval, C.; ISTerre, Université Joseph Fourier, CNRS, BP 53, 38041 Grenoble, France ;Drouet, S.; ISTerre, Université Joseph Fourier, CNRS, BP 53, 38041 Grenoble, France ;Douglas, J.; RIS/RSI, BRGM, 3 avenue C. Guillemin, BP 36009, 45060 Orléans Cedex 2, France ;Basili, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Sandikkaya, M. A.; Earthquake Engineering Research Center, Department of Civil Engineering, METU, 06531 Ankara, Turkey ;Segou, M.; Earthquake Engineering Research Center, Department of Civil Engineering, METU, 06531 Ankara, Turkey ;Faccioli, E.; Politecnico di Milano, Piazza L. da Vinci, 32, 20133 Milan, Italy ;Theodoulidis, N.; ITSAK, P.O. Box 53, Finikas 55102 Thessaloniki, Greece; ; ; ; ; ; ; ; ; ; ; ; The Seismic Hazard Harmonization in Europe (SHARE) project, which began in June 2009, aims at establishing new standards for probabilistic seismic hazard assessment in the Euro-Mediterranean region. In this context, a logic tree for ground-motion prediction in Europe has been constructed. Ground-motion prediction equations (GMPEs) and weights have been determined so that the logic tree captures epistemic uncertainty in ground-motion prediction for six different tectonic regimes in Europe. Here we present the strategy that we adopted to build such a logic tree. This strategy has the particularity of combining two complementary and independent approaches: expert judgment and data testing. A set of six experts was asked to weight pre-selected GMPEs while the ability of these GMPEs to predict available data was evaluated with the method of Scherbaum et al. (Bull Seismol Soc Am 99:3234–3247, 2009). Results of both approaches were taken into account to commonly select the smallest set of GMPEs to capture the uncertainty in ground-motion prediction in Europe. For stable continental regions, two models, both from eastern North America, have been selected for shields, and three GMPEs from active shallow crustal regions have been added for continental crust. For subduction zones, four models, all non-European, have been chosen. Finally, for active shallow crustal regions, we selected four models, each of them from a different host region but only two of them were kept for long periods. In most cases, a common agreement has been also reached for the weights. In case of divergence, a sensitivity analysis of the weights on the seismic hazard has been conducted, showing that once the GMPEs have been selected, the associated set of weights has a smaller influence on the hazard.258 20