@article{GruenthalStromeyerBosseetal.2018, author = {Gr{\"u}nthal, Gottfried and Stromeyer, Dietrich and Bosse, Christian and Cotton, Fabrice Pierre and Bindi, Dino}, title = {The probabilistic seismic hazard assessment of Germany-version 2016, considering the range of epistemic uncertainties and aleatory variability}, series = {Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering}, volume = {16}, journal = {Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering}, number = {10}, publisher = {Springer}, address = {Dordrecht}, issn = {1570-761X}, doi = {10.1007/s10518-018-0315-y}, pages = {4339 -- 4395}, year = {2018}, abstract = {The basic seismic load parameters for the upcoming national design regulation for DIN EN 1998-1/NA result from the reassessment of the seismic hazard supported by the German Institution for Civil Engineering (DIBt). This 2016 version of the national seismic hazard assessment for Germany is based on a comprehensive involvement of all accessible uncertainties in models and parameters and includes the provision of a rational framework for integrating ranges of epistemic uncertainties and aleatory variabilities in a comprehensive and transparent way. The developed seismic hazard model incorporates significant improvements over previous versions. It is based on updated and extended databases, it includes robust methods to evolve sets of models representing epistemic uncertainties, and a selection of the latest generation of ground motion prediction equations. The new earthquake model is presented here, which consists of a logic tree with 4040 end branches and essential innovations employed for a realistic approach. The output specifications were designed according to the user oriented needs as suggested by two review teams supervising the entire project. Seismic load parameters, for rock conditions of nu(S30) = 800 m/s, are calculated for three hazard levels (10, 5 and 2\% probability of occurrence or exceedance within 50 years) and delivered in the form of uniform hazard spectra, within the spectral period range 0.02-3 s, and seismic hazard maps for peak ground acceleration, spectral response accelerations and for macroseismic intensities. Results are supplied as the mean, the median and the 84th percentile. A broad analysis of resulting uncertainties of calculated seismic load parameters is included. The stability of the hazard maps with respect to previous versions and the cross-border comparison is emphasized.}, language = {en} } @article{LanzanoSgobbaLuzietal.2018, author = {Lanzano, Giovanni and Sgobba, Sara and Luzi, Lucia and Puglia, Rodolfo and Pacor, Francesca and Felicetta, Chiara and Cotton, Fabrice Pierre and Bindi, Dino}, title = {The pan-European Engineering Strong Motion (ESM) flatfile}, series = {Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering}, volume = {17}, journal = {Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering}, number = {2}, publisher = {Springer}, address = {Dordrecht}, issn = {1570-761X}, doi = {10.1007/s10518-018-0480-z}, pages = {561 -- 582}, year = {2018}, abstract = {The Engineering Strong-Motion (ESM) flatfile is a parametric table which contains verified and reliable metadata and intensity measures of manually processed waveforms included in the ESM database. The flatfile has been developed within the Seismology Thematic Core Service of EPOS-IP (European Plate Observing System Implementation Phase) and it is disseminated throughout a web portal for research and technical purposes. The adopted criteria for flatfile compilation aim to collect strong motion data and related metadata in a uniform, updated, traceable and quality-checked way to develop Ground Motion Models (GMMs) for Probabilistic Seismic Hazard Assessment (PSHA) and engineering applications. In this paper, we present the characteristics of ESM flatfile in terms of recording, event and station distributions, and we discuss the most relevant features of the Intensity Measures (IMs) of engineering interest included in the table. The dataset for flatfile compilation includes 23,014 recordings from 2179 earthquakes and 2080 stations from Europe and Middle-East. The events are characterized by magnitudes in the range 3.5-8.0 and refer to different tectonics regimes, such as shallow active crustal and subduction zones. Intensity measures include peak and integral parameters and duration of each waveform. The spectral amplitudes of the (5\% damping) acceleration and displacement response are provided for 36 periods, in the interval 0.01-10 s, as well as the 103 amplitudes of the Fourier spectrum for the frequency range 0.04-50 Hz. Several statistics are shown with reference to the most significant metadata for GMMs calibrations, such as moment magnitude, focal depth, several distance metrics, style of faulting and parameters for site characterization. Furthermore, we also compare and explain the most relevant differences between the metadata of ESM flatfile with those provided by the previous flatfile derived in RESORCE (Reference Database for Seismic Ground Motion in Europe) project.}, language = {en} } @article{BindiKothaWeatherilletal.2018, author = {Bindi, Dino and Kotha, Sreeram Reddy and Weatherill, Graeme and Lanzano, Giovanni and Luzi, Lucia and Cotton, Fabrice Pierre}, title = {The pan-European engineering strong motion (ESM) flatfile}, series = {Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering}, volume = {17}, journal = {Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering}, number = {2}, publisher = {Springer}, address = {Dordrecht}, issn = {1570-761X}, doi = {10.1007/s10518-018-0466-x}, pages = {583 -- 602}, year = {2018}, abstract = {We present the results of a consistency check performed over the flatfile extracted from the engineering strong motion (ESM) database. The flatfile includes 23,014 recordings from 2179 earthquakes in the magnitude range from 3.5 to 7.8 that occurred since the 1970s in Europe and Middle East, as presented in the companion article by Lanzano et al. (Bull Earthq Eng, 2018a). The consistency check is developed by analyzing different residual distributions obtained from ad-hoc ground motion prediction equations for the absolute spectral acceleration (SA), displacement and Fourier amplitude spectra (FAS). Only recordings from earthquakes shallower than 40 km are considered in the analysis. The between-event, between-station and event-and-station corrected residuals are computed by applying a mixed-effect regression. We identified those earthquakes, stations, and recordings showing the largest deviations from the GMPE median predictions, and also evaluated the statistical uncertainty on the median model to get insights on the applicable magnitude-distance ranges and the usable period (or frequency) range. We observed that robust median predictions are obtained up to 8 s for SA and up to 20 Hz for FAS, although median predictions for Mw ≥ 7 show significantly larger uncertainties with 'bumps' starting above 5 s for SA and below 0.3 Hz for FAS. The between-station variance dominates over the other residual variances, and the dependence of the between-station residuals on logarithm of Vs30 is well-described by a piece-wise linear function with period-dependent slopes and hinge velocity around 580 m/s. Finally, we compared the between-event residuals obtained by considering two different sources of moment magnitude. The results show that, at long periods, the between-event terms from the two regressions have a weak correlation and the overall between-event variability is dissimilar, highlighting the importance of magnitude source in the regression results.}, language = {en} } @article{BindiCottonSpallarossaetal.2018, author = {Bindi, Dino and Cotton, Fabrice Pierre and Spallarossa, Daniele and Picozzi, Matteo and Rivalta, Eleonora}, title = {Temporal variability of ground shaking and stress drop in Central Italy}, series = {Bulletin of the Seismological Society of America}, volume = {108}, journal = {Bulletin of the Seismological Society of America}, number = {4}, publisher = {Seismological Society of America}, address = {Albany}, issn = {0037-1106}, doi = {10.1785/0120180078}, pages = {1853 -- 1863}, year = {2018}, abstract = {Ground-motion prediction equations (GMPEs) are calibrated to predict the intensity of ground shaking at any given location, based on earthquake magnitude, source-to-site distance, local soil amplifications, and other parameters. GMPEs are generally assumed to be independent of time; however, evidence is increasing that large earthquakes modify the shallow soil conditions and those of the fault zone for months or years. These changes may affect the intensity of shaking and result in time-dependent effects that can potentially be resolved by analyzing between-event residuals (residuals between observed and predicted ground motion for individual earthquakes averaged over all stations). Here, we analyze a data set of about 65,000 recordings for about 1400 earthquakes in the moment magnitude range 2.5-6.5 that occurred in central Italy from 2008 to 2017 to capture the temporal variability of the ground shaking at high frequency. We first compute between-event residuals for each earthquake in the Fourier domain with respect to a GMPE developed ad hoc for the analyzed data set. The between-events show large changes after the occurrence of mainshocks such as the 2009 Mw 6.3 L'Aquila, the 2016 Mw 6.2 Amatrice, and Mw 6.5 Norcia earthquakes. Within the time span of a few months after the mainshocks, the between-event contribution to the ground shaking varies by a factor 7. In particular, we find a large drop in the between-events in the aftermath of the L'Aquila earthquake, followed by a slow positive trend that leads to a recovery interrupted by a new drop at the beginning of 2014. We also quantify the frequency-dependent correlation between the Brune stress drop Δσ and the between-events. We find that the temporal changes of Δσ resemble those of the between-event residuals; in particular, during the period when the between-events show the positive trend, the average logarithm of Δσ increases with an annual rate of 0.19 (i.e., the amplification factor for Δσ is 1.56 per year). Breakpoint analysis located a change in the linear trend coefficients of Δσ versus time in February 2014, although no large earthquakes occurred at that time. Finally, the temporal variability of Δσ mirrors the relative seismic-velocity variations observed in previous studies for the same area and period, suggesting that both crack healing along the main fault system and healing of microcracks distributed at shallow depths throughout the surrounding region might be necessary to explain the wider observations of postearthquake recovery.}, language = {en} } @article{DahmHeimannFunkeetal.2018, author = {Dahm, Torsten and Heimann, Sebastian and Funke, Sigward and Wendt, Siegfried and Rappsilber, Ivo and Bindi, Dino and Plenefisch, Thomas and Cotton, Fabrice Pierre}, title = {Seismicity in the block mountains between Halle and Leipzig, Central Germany}, series = {Journal of seismology}, volume = {22}, journal = {Journal of seismology}, number = {4}, publisher = {Springer}, address = {Dordrecht}, issn = {1383-4649}, doi = {10.1007/s10950-018-9746-9}, pages = {985 -- 1003}, year = {2018}, abstract = {On April 29, 2017 at 0:56 UTC (2:56 local time), an M (W) = 2.8 earthquake struck the metropolitan area between Leipzig and Halle, Germany, near the small town of Markranstadt. The earthquake was felt within 50 km from the epicenter and reached a local intensity of I (0) = IV. Already in 2015 and only 15 km northwest of the epicenter, a M (W) = 3.2 earthquake struck the area with a similar large felt radius and I (0) = IV. More than 1.1 million people live in the region, and the unusual occurrence of the two earthquakes led to public attention, because the tectonic activity is unclear and induced earthquakes have occurred in neighboring regions. Historical earthquakes south of Leipzig had estimated magnitudes up to M (W) ae 5 and coincide with NW-SE striking crustal basement faults. We use different seismological methods to analyze the two recent earthquakes and discuss them in the context of the known tectonic structures and historical seismicity. Novel stochastic full waveform simulation and inversion approaches are adapted for the application to weak, local earthquakes, to analyze mechanisms and ground motions and their relation to observed intensities. We find NW-SE striking normal faulting mechanisms for both earthquakes and centroid depths of 26 and 29 km. The earthquakes are located where faults with large vertical offsets of several hundred meters and Hercynian strike have developed since the Mesozoic. We use a stochastic full waveform simulation to explain the local peak ground velocities and calibrate the method to simulate intensities. Since the area is densely populated and has sensitive infrastructure, we simulate scenarios assuming that a 12-km long fault segment between the two recent earthquakes is ruptured and study the impact of rupture parameters on ground motions and expected damage.}, language = {en} } @article{BindiSpallarossaPicozzietal.2018, author = {Bindi, Dino and Spallarossa, D. and Picozzi, M. and Scafidi, D. and Cotton, Fabrice Pierre}, title = {Impact of magnitude selection on aleatory variability associated with ground-motion prediction equations}, series = {Bulletin of the Seismological Society of America}, volume = {108}, journal = {Bulletin of the Seismological Society of America}, number = {3A}, publisher = {Seismological Society of America}, address = {Albany}, issn = {0037-1106}, doi = {10.1785/0120170356}, pages = {1427 -- 1442}, year = {2018}, abstract = {In this study, we analyzed 10 yrs of seismicity in central Italy from 2008 to 2017, a period witnessing more than 1400 earthquakes in the magnitude range 2.5≤Mw≤6.5⁠. The data set includes the main sequences that have occurred in the area, including those associated with the 2009 Mw 6.3 L'Aquila earthquake and the 2016-2017 sequence (⁠Mw 6.2 Amatrice, Mw 6.1 Visso, and Mw 6.5 Norcia earthquakes). We calibrated a local magnitude scale, investigating the impact of changing the reference distance at which the nonparametric attenuation is tied to the zero-magnitude attenuation function for southern California. We also developed an attenuation model to compute the radiated seismic energy (⁠Es⁠) from the time integral of the squared ground-motion velocity. Seismic moment (⁠M0⁠) and stress drop (⁠Δσ⁠) were estimated for each earthquake by fitting a ω-square model to the source spectra obtained by applying a nonparametric spectral inversion. The Δσ-values vary over three orders of magnitude from about 0.1 to 10 MPa, the larger values associated with the mainshocks. The Δσ-values describe a lognormal distribution with mean and standard deviation equal to log(Δσ)=(-0.25±0.45) (i.e., the mean Δσ is 0.57 MPa, with a 95\% confidence interval from 0.08 to 4.79 MPa). The Δσ variability introduces a spread in the distribution of seismic energy versus moment, with differences in energy up two orders of magnitudes for earthquakes with the same moment. The variability in the high-frequency spectral levels is captured by the local magnitude (⁠ML⁠), which scales with radiated energy as ML=(-1.59+0.52logEs) for logEs≤10.26 and ML=(-1.38+0.50logEs) otherwise. As the peak ground velocity increases with increasing Δσ⁠, local and energy magnitudes perform better than moment magnitude as predictors for the shaking potential. The availability of different magnitude scales and source parameters for a large earthquake population will help characterize the between-event ground-motion variability in central Italy.}, language = {en} } @misc{GruenthalStromeyerBosseetal.2018, author = {Gr{\"u}nthal, Gottfried and Stromeyer, Dietrich and Bosse, Christian and Cotton, Fabrice Pierre and Bindi, Dino}, title = {Correction to: The probabilistic seismic hazard assessment of Germanyversion 2016, considering the range of epistemic uncertainties and aleatory variability (vol 16, pg 4339, 2018)}, series = {Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering}, volume = {16}, journal = {Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering}, number = {10}, publisher = {Springer}, address = {Dordrecht}, issn = {1570-761X}, doi = {10.1007/s10518-018-0398-5}, pages = {4397 -- 4398}, year = {2018}, abstract = {One paragraph of the manuscript of the paper has been inadvertently omitted in the very final stage of its compilation due to a technical mistake. Since this paragraph discusses the declustering of the used earthquake catalogue and is therefore necessary for the understanding of the seismicity data preprocessing, the authors decided to provide this paragraph in form of a correction. The respective paragraph belongs to chapter 2 of the paper, where it was placed originally, and should be inserted into the published paper before the second to the last paragraph. The omitted text reads as follows:}, language = {en} } @misc{DahmHeimannFunkeetal.2018, author = {Dahm, Torsten and Heimann, Sebastian and Funke, Sigward and Wendt, Siegfried and Rappsilber, Ivo and Bindi, Dino and Plenefisch, Thomas and Cotton, Fabrice Pierre}, title = {Correction to: Seismicity in the block mountains between Halle and Leipzig, Central Germany: centroid moment tensors, ground motion simulation, and felt intensities of two M approximate to 3 earthquakes in 2015 and 2017 (vol 22, pg 985, 2018)}, series = {Journal of seismology}, volume = {22}, journal = {Journal of seismology}, number = {6}, publisher = {Springer}, address = {Dordrecht}, issn = {1383-4649}, doi = {10.1007/s10950-018-9773-6}, pages = {1669 -- 1671}, year = {2018}, language = {en} } @article{KothaCottonBindi2018, author = {Kotha, Sreeram Reddy and Cotton, Fabrice Pierre and Bindi, Dino}, title = {A new approach to site classification}, series = {Soil Dynamics and Earthquake Engineering}, volume = {110}, journal = {Soil Dynamics and Earthquake Engineering}, publisher = {Elsevier}, address = {Oxford}, issn = {0267-7261}, doi = {10.1016/j.soildyn.2018.01.051}, pages = {318 -- 329}, year = {2018}, abstract = {With increasing amount of strong motion data, Ground Motion Prediction Equation (GMPE) developers are able to quantify empirical site amplification functions (delta S2S(s)) from GMPE residuals, for use in site-specific Probabilistic Seismic Hazard Assessment. In this study, we first derive a GMPE for 5\% damped Pseudo Spectral Acceleration (g) of Active Shallow Crustal earthquakes in Japan with 3.4 <= M-w <= 7.3 and 0 <= R-JB <= 600km. Using k-mean spectral clustering technique, we then classify our estimated delta S2S(s)(T = 0.01 - 2s) of 588 wellcharacterized sites, into 8 site clusters with distinct mean site amplification functions, and within-cluster site-tosite variability similar to 50\% smaller than the overall dataset variability (phi(S2S)). Following an evaluation of existing schemes, we propose a revised data-driven site classification characterized by kernel density distributions of V-s30, V-s10, H-800, and predominant period (T-G) of the site clusters.}, language = {en} }