TY - JOUR A1 - Kummerow, J. A1 - Kind, Rainer A1 - Oncken, Onno A1 - Giese, Peter A1 - Ryberg, Trond A1 - Wylegalla, Kurt A1 - Scherbaum, Frank T1 - A natural and controlled source seismic profile through the Eastern Alps : TRANSALP N2 - The combined passive and active seismic TRANSALP experiment produced an unprecedented high-resolution crustal image of the Eastern Alps between Munich and Venice. The European and Adriatic Mohos (EM and AM, respectively) are clearly imaged with different seismic techniques: near-vertical incidence reflections and receiver functions (RFs). The European Moho dips gently southward from 35 km beneath the northern foreland to a maximum depth of 55 km beneath the central part of the Eastern Alps, whereas the Adriatic Moho is imaged primarily by receiver functions at a relatively constant depth of about 40 km. In both data sets, we have also detected first-order Alpine shear zones, such as the Helvetic detachment, Inntal fault and SubTauern ramp in the north. Apart from the Valsugana thrust, receiver functions in the southern part of the Eastern Alps have also observed a north dipping interface, which may penetrate the entire Adriatic crust [Adriatic Crust Interface (ACI)]. Deep crustal seismicity may be related to the ACI. We interpret the ACI as the currently active retroshear zone in the doubly vergent Alpine collisional belt. (C) 2004 Elsevier B.V. All rights reserved Y1 - 2004 ER - TY - JOUR A1 - Hinzen, K. G. A1 - Weber, B. A1 - Scherbaum, Frank T1 - On the resolution of H/V measurements to determine sediment thickness, a case study across a normal fault in the Lower Rhine Embayment, Germany N2 - In recent years, H/V measurements have been increasingly used to map the thickness of sediment fill in sedimentary basins in the context of seismic hazard assessment. This parameter is believed to be an important proxy for the site effects in sedimentary basins (e.g. in the Los Angeles basin). Here we present the results of a test using this approach across an active normal fault in a structurally well known situation. Measurements on a 50 km long profile with 1 km station spacing clearly show a change in the frequency of the fundamental peak of H/V ratios with increasing thickness of the sediment layer in the eastern part of the Lower Rhine Embayment. Subsequently, a section of 10 km length across the Erft-Sprung system, a normal fault with ca. 750 m vertical offset, was measured with a station distance of 100 m. Frequencies of the first and second peaks and the first trough in the H/V spectra are used in a simple resonance model to estimate depths of the bedrock. While the frequency of the first peak shows a large scatter for sediment depths larger than ca. 500 m, the frequency of the first trough follows the changing thickness of the sediments across the fault. The lateral resolution is in the range of the station distance of 100 m. A power law for the depth dependence of the S-wave velocity derived from down hole measurements in an earlier study [Budny, 1984] and power laws inverted from dispersion analysis of micro array measurements [Scherbaum et al., 2002] agree with the results from the H/V ratios of this study Y1 - 2004 SN - 1363-2469 ER - TY - JOUR A1 - Malischewsky, Peter G. A1 - Scherbaum, Frank T1 - Love's formula and H/V-ratio (ellipticity) of Rayleigh waves N2 - The ellipticity of Rayleigh surface waves, which is an important parameter characterizing the propagation medium, is studied for several models with increasing complexity. While the main focus lies on theory, practical implications of the use of the horizontal to vertical component ratio (H/V-ratio) to Study the subsurface structure are considered as well. Love's approximation of the ellipticity for an incompressible layer over an incompressible half-space is critically discussed especially concerning its applicability for different impedance contrasts. The main result is an analytically exact formula of H/V for a 2-layer model of compressible media, which is a generalization of Love's formula. It turns out that for a limited range of models Love's approximation can be used also in the general case. (C) 2003 Elsevier B.V. All rights reserved Y1 - 2004 SN - 0165-2125 ER - TY - JOUR A1 - Falsaperla, Susanna A1 - Wassermann, Joachim A1 - Scherbaum, Frank T1 - Solid earth - 29. Polarization analyses of broadband seismic data recorded on Stromboli Volcano (Italy) from 1996 to 1999 (DOI 10.1029-2001GLO14300) Y1 - 2002 ER - TY - CHAP A1 - Hainzl, Sebastian A1 - Scherbaum, Frank A1 - Zöller, Gert T1 - Spatiotemporal earthquake patterns N2 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006 Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7267 N1 - [Poster] ER - TY - GEN A1 - Hiemer, Stefan A1 - Rößler, Dirk A1 - Scherbaum, Frank T1 - Catalog of Swarm Earthquakes in Vogtland /West Bohemia in 2008/09 N2 - The document contains the catalog of earthquakes in Vogtland /West Bohemia within the period of 2008/10/19 -to- 2009/03/16. The events were recorded by a seismic mini-array operated by the Institute of Earthsciences, University of Postdam. N2 - Das Dokument enthält einen Katalog von Erdbeben im Vogtland/Westböhmen im Zeitraum 2008/10/19 -bis- 2009/03/16. Die Erdbeben wurden mit Hilfe eines seismologischen Miniarrays, welches vom Institut für Geowissenschaften, Universität Potsdam, aufgestellt wurde, registriert. KW - Vogtland/Westböhmen KW - Erdbebenschwarm 2008/09 KW - Arrayseismologie KW - Erdbebenkatalog KW - Vogtland/West Bohemia KW - earthquake swarm 2008/09 KW - array seismology KW - earthquake catalog Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-51710 ER - TY - GEN A1 - Hiemer, Stefan A1 - Rößler, Dirk A1 - Scherbaum, Frank T1 - Catalog of Swarm Earthquakes in Vogtland /West Bohemia in 2008/09 N2 - The document contains the catalog of earthquakes in Vogtland /West Bohemia within the period of 2008/10/19 -to- 2009/03/16. The events were recorded by a seismic mini-array operated by the Institute of Earthsciences, University of Postdam. N2 - Das Dokument enthält einen Katalog von Erdbeben im Vogtland/Westböhmen im Zeitraum 2008/10/19 -bis- 2009/03/16. Die Erdbeben wurden mit Hilfe eines seismologischen Miniarrays, welches vom Institut für Geowissenschaften, Universität Potsdam, aufgestellt wurde, registriert. KW - Vogtland/Westböhmen KW - Erdbebenschwarm 2008/09 KW - Arrayseismologie KW - Erdbebenkatalog KW - Vogtland/West Bohemia KW - earthquake swarm 2008/09 KW - array seismology KW - earthquake catalog Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-53837 ER - TY - BOOK A1 - Scherbaum, Frank A1 - Mzhavanadze, Nana A1 - Arom, Simha A1 - Rosenzweig, Sebastian A1 - Müller, Meinard ED - Scherbaum, Frank T1 - Tonal Organization of the Erkomaishvili Dataset: Pitches, Scales, Melodies and Harmonies T3 - Computational Analysis Of Traditional Georgian Vocal Music N2 - In this study we examine the tonal organization of a series of recordings of liturgical chants, sung in 1966 by the Georgian master singer Artem Erkomaishvili. This dataset is the oldest corpus of Georgian chants from which the time synchronous F0-trajectories for all three voices have been reliably determined (Müller et al. 2017). It is therefore of outstanding importance for the understanding of the tuning principles of traditional Georgian vocal music. The aim of the present study is to use various computational methods to analyze what these recordings can contribute to the ongoing scientific dispute about traditional Georgian tuning systems. Starting point for the present analysis is the re-release of the original audio data together with estimated fundamental frequency (F0) trajectories for each of the three voices, beat annotations, and digital scores (Rosenzweig et al. 2020). We present synoptic models for the pitch and the harmonic interval distributions, which are the first of such models for which the complete Erkomaishvili dataset was used. We show that these distributions can be very compactly be expressed as Gaussian mixture models, anchored on discrete sets of pitch or interval values for the pitch and interval distributions, respectively. As part of our study we demonstrate that these pitch values, which we refer to as scale pitches, and which are determined as the mean values of the Gaussian mixture elements, define the scale degrees of the melodic sound scales which build the skeleton of Artem Erkomaishvili’s intonation. The observation of consistent pitch bending of notes in melodic phrases, which appear in identical form in a group of chants, as well as the observation of harmonically driven intonation adjustments, which are clearly documented for all pure harmonic intervals, demonstrate that Artem Erkomaishvili intentionally deviates from the scale pitch skeleton quite freely. As a central result of our study, we proof that this melodic freedom is always constrained by the attracting influence of the scale pitches. Deviations of the F0-values of individual note events from the scale pitches at one instance of time are compensated for in the subsequent melodic steps. This suggests a deviation-compensation mechanism at the core of Artem Erkomaishvili’s melody generation, which clearly honors the scales but still allows for a large degree of melodic flexibility. This model, which summarizes all partial aspects of our analysis, is consistent with the melodic scale models derived from the observed pitch distributions, as well as with the melodic and harmonic interval distributions. In addition to the tangible results of our work, we believe that our work has general implications for the determination of tuning models from audio data, in particular for non-tempered music. T3 - Computational Analysis Of Traditional Georgian Vocal Music - 1 KW - computational ethnomusicology KW - traditional Georgian music KW - Georgian chant KW - Artem Erkomaishvili KW - musical scales KW - computergestützte Musikethnologie KW - traditionelle Georgische Musik KW - Georgische liturgische Gesänge KW - Artem Erkomaishvili KW - musikalische Tonleitern Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-476141 SN - 2702-2641 IS - 1 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Vogel, Kristin A1 - Riggelsen, Carsten A1 - Korup, Oliver A1 - Scherbaum, Frank T1 - Bayesian network learning for natural hazard analyses JF - Natural hazards and earth system sciences N2 - Modern natural hazards research requires dealing with several uncertainties that arise from limited process knowledge, measurement errors, censored and incomplete observations, and the intrinsic randomness of the governing processes. Nevertheless, deterministic analyses are still widely used in quantitative hazard assessments despite the pitfall of misestimating the hazard and any ensuing risks. In this paper we show that Bayesian networks offer a flexible framework for capturing and expressing a broad range of uncertainties encountered in natural hazard assessments. Although Bayesian networks are well studied in theory, their application to real-world data is far from straightforward, and requires specific tailoring and adaptation of existing algorithms. We offer suggestions as how to tackle frequently arising problems in this context and mainly concentrate on the handling of continuous variables, incomplete data sets, and the interaction of both. By way of three case studies from earthquake, flood, and landslide research, we demonstrate the method of data-driven Bayesian network learning, and showcase the flexibility, applicability, and benefits of this approach. Our results offer fresh and partly counterintuitive insights into well-studied multivariate problems of earthquake-induced ground motion prediction, accurate flood damage quantification, and spatially explicit landslide prediction at the regional scale. In particular, we highlight how Bayesian networks help to express information flow and independence assumptions between candidate predictors. Such knowledge is pivotal in providing scientists and decision makers with well-informed strategies for selecting adequate predictor variables for quantitative natural hazard assessments. Y1 - 2014 U6 - https://doi.org/10.5194/nhess-14-2605-2014 SN - 1561-8633 VL - 14 IS - 9 SP - 2605 EP - 2626 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Hinzen, Klaus-G A1 - Reamer, Sharon K. A1 - Scherbaum, Frank T1 - Slow fourier transform JF - Seismological research letters Y1 - 2013 U6 - https://doi.org/10.1785/0220120139 SN - 0895-0695 VL - 84 IS - 2 SP - 251 EP - 257 PB - Seismological Society of America CY - Albany ER - TY - JOUR A1 - Kühn, Nicolas M. A1 - Scherbaum, Frank A1 - Riggelsen, Carsten T1 - Deriving empirical ground-motion models : balancing data constraints and physical assumptions to optimize prediction capability N2 - Empirical ground-motion models used in seismic hazard analysis are commonly derived by regression of observed ground motions against a chosen set of predictor variables. Commonly, the model building process is based on residual analysis and/or expert knowledge and/or opinion, while the quality of the model is assessed by the goodness-of-fit to the data. Such an approach, however, bears no immediate relation to the predictive power of the model and with increasing complexity of the models is increasingly susceptible to the danger of overfitting. Here, a different, primarily data-driven method for the development of ground-motion models is proposed that makes use of the notion of generalization error to counteract the problem of overfitting. Generalization error directly estimates the average prediction error on data not used for the model generation and, thus, is a good criterion to assess the predictive capabilities of a model. The approach taken here makes only few a priori assumptions. At first, peak ground acceleration and response spectrum values are modeled by flexible, nonphysical functions (polynomials) of the predictor variables. The inclusion of a particular predictor and the order of the polynomials are based on minimizing generalization error. The approach is illustrated for the next generation of ground-motion attenuation dataset. The resulting model is rather complex, comprising 48 parameters, but has considerably lower generalization error than functional forms commonly used in ground-motion models. The model parameters have no physical meaning, but a visual interpretation is possible and can reveal relevant characteristics of the data, for example, the Moho bounce in the distance scaling. In a second step, the regression model is approximated by an equivalent stochastic model, making it physically interpretable. The resulting resolvable stochastic model parameters are comparable to published models for western North America. In general, for large datasets generalization error minimization provides a viable method for the development of empirical ground-motion models. Y1 - 2009 UR - http://bssa.geoscienceworld.org/ U6 - https://doi.org/10.1785/0120080136 SN - 0037-1106 ER - TY - JOUR A1 - Delavaud, Elise A1 - Scherbaum, Frank A1 - Kuehn, Nicolas A1 - Riggelsen, Carsten T1 - Information-theoretic selection of ground-motion prediction equations for seismic hazard analysis : an applicability study using Californian data N2 - Considering the increasing number and complexity of ground-motion prediction equations available for seismic hazard assessment, there is a definite need for an efficient, quantitative, and robust method to select and rank these models for a particular region of interest. In a recent article, Scherbaum et al. (2009) have suggested an information- theoretic approach for this purpose that overcomes several shortcomings of earlier attempts at using data-driven ground- motion prediction equation selection procedures. The results of their theoretical study provides evidence that in addition to observed response spectra, macroseismic intensity data might be useful for model selection and ranking. We present here an applicability study for this approach using response spectra and macroseismic intensities from eight Californian earthquakes. A total of 17 ground-motion prediction equations, from different regions, for response spectra, combined with the equation of Atkinson and Kaka (2007) for macroseismic intensities are tested for their relative performance. The resulting data-driven rankings show that the models that best estimate ground motion in California are, as one would expect, Californian and western U. S. models, while some European models also perform fairly well. Moreover, the model performance appears to be strongly dependent on both distance and frequency. The relative information of intensity versus response spectral data is also explored. The strong correlation we obtain between intensity-based rankings and spectral-based ones demonstrates the great potential of macroseismic intensities data for model selection in the context of seismic hazard assessment. Y1 - 2009 UR - http://bssa.geoscienceworld.org/ U6 - https://doi.org/10.1785/0120090055 SN - 0037-1106 ER - TY - JOUR A1 - Faenza, Licia A1 - Hainzl, Sebastian A1 - Scherbaum, Frank T1 - Statistical analysis of the Central-Europe seismicity N2 - 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 conspicuous characteristics of M-w 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. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00401951 U6 - https://doi.org/10.1016/j.tecto.2008.04.030 SN - 0040-1951 ER - TY - JOUR A1 - Wassermann, Joachim A1 - Ohrnberger, Matthias A1 - Scherbaum, Frank A1 - Gossler, J. A1 - Zschau, Jochen T1 - Kontinuierliche seismologische Netz- und Arraymessungen am Dekadenvulkan Merapi (Java, Indonesien) : ein Zwischenresümee = Continuous measurements at Merapi volcano (Java, Indonesia) using anetwork of small-scale seismograph arrays Y1 - 1998 SN - 0947-1944 ER - TY - JOUR A1 - Koehler, Andreas A1 - Ohrnberger, Matthias A1 - Scherbaum, Frank T1 - Unsupervised feature selection and general pattern discovery using Self-Organizing Maps for gaining insights into the nature of seismic wavefields N2 - This study presents an unsupervised feature selection and learning approach for the discovery and intuitive imaging of significant temporal patterns in seismic single-station or network recordings. For this purpose, the data are parametrized by real-valued feature vectors for short time windows using standard analysis tools for seismic data, such as frequency-wavenumber, polarization, and spectral analysis. We use Self-Organizing Maps (SOMs) for a data-driven feature selection, visualization and clustering procedure, which is in particular suitable for high-dimensional data sets. Our feature selection method is based on significance testing using the Wald-Wolfowitz runs test for-individual features and on correlation hunting with SOMs in feature subsets. Using synthetics composed of Rayleigh and Love waves and real-world data, we show the robustness and the improved discriminative power of that approach compared to feature subsets manually selected from individual wavefield parametrization methods. Furthermore, the capability of the clustering and visualization techniques to investigate the discrimination of wave phases is shown by means of synthetic waveforms and regional earthquake recordings. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00983004 U6 - https://doi.org/10.1016/j.cageo.2009.02.004 SN - 0098-3004 ER - TY - JOUR A1 - Runge, Antonia K. A1 - Scherbaum, Frank A1 - Curtis, Andrew A1 - Riggelsen, Carsten T1 - An interactive tool for the elicitation of subjective probabilities in probabilistic seismic-hazard analysis JF - Bulletin of the Seismological Society of America N2 - In probabilistic seismic-hazard analysis, epistemic uncertainties are commonly treated within a logic-tree framework in which the branch weights express the degree of belief of an expert in a set of models. For the calculation of the distribution of hazard curves, these branch weights represent subjective probabilities. A major challenge for experts is to provide logically consistent weight estimates (in the sense of Kolmogorovs axioms), to be aware of the multitude of heuristics, and to minimize the biases which affect human judgment under uncertainty. We introduce a platform-independent, interactive program enabling us to quantify, elicit, and transfer expert knowledge into a set of subjective probabilities by applying experimental design theory, following the approach of Curtis and Wood (2004). Instead of determining the set of probabilities for all models in a single step, the computer-driven elicitation process is performed as a sequence of evaluations of relative weights for small subsets of models. From these, the probabilities for the whole model set are determined as a solution of an optimization problem. The result of this process is a set of logically consistent probabilities together with a measure of confidence determined from the amount of conflicting information which is provided by the expert during the relative weighting process. We experiment with different scenarios simulating likely expert behaviors in the context of knowledge elicitation and show the impact this has on the results. The overall aim is to provide a smart elicitation technique, and our findings serve as a guide for practical applications. Y1 - 2013 U6 - https://doi.org/10.1785/0120130026 SN - 0037-1106 SN - 1943-3573 VL - 103 IS - 5 SP - 2862 EP - 2874 PB - Seismological Society of America CY - Albany ER - TY - JOUR A1 - Scherbaum, Frank A1 - Bouin, M. P. T1 - FIR filter effects and nucleation phases Y1 - 1997 ER - TY - JOUR A1 - Scherbaum, Frank T1 - Zero Phase FIR filters in digital seismic acquisition systems : blessing or curse Y1 - 1997 ER - TY - JOUR A1 - Scherbaum, Frank A1 - Delavaud, Elise A1 - Riggelsen, Carsten T1 - Model selection in seismic hazard analysis : an information-theoretic perspective N2 - Although the methodological framework of probabilistic seismic hazard analysis is well established, the selection of models to predict the ground motion at the sites of interest remains a major challenge. Information theory provides a powerful theoretical framework that can guide this selection process in a consistent way. From an information- theoretic perspective, the appropriateness of models can be expressed in terms of their relative information loss (Kullback-Leibler distance) and hence in physically meaningful units (bits). In contrast to hypothesis testing, information-theoretic model selection does not require ad hoc decisions regarding significance levels nor does it require the models to be mutually exclusive and collectively exhaustive. The key ingredient, the Kullback-Leibler distance, can be estimated from the statistical expectation of log-likelihoods of observations for the models under consideration. In the present study, data-driven ground-motion model selection based on Kullback-Leibler-distance differences is illustrated for a set of simulated observations of response spectra and macroseismic intensities. Information theory allows for a unified treatment of both quantities. The application of Kullback-Leibler-distance based model selection to real data using the model generating data set for the Abrahamson and Silva (1997) ground-motion model demonstrates the superior performance of the information-theoretic perspective in comparison to earlier attempts at data- driven model selection (e.g., Scherbaum et al., 2004). Y1 - 2009 UR - http://bssa.geoscienceworld.org/ U6 - https://doi.org/10.1785/0120080347 SN - 0037-1106 ER - TY - JOUR A1 - Rietbrock, Andreas A1 - Scherbaum, Frank T1 - Crustal scattering at the KTB from a combined microearthquake and receiver analysis Y1 - 1998 ER -