@article{BeauvalHainzlScherbaum2006,
  author    = {Beauval, Celine and Hainzl, Sebastian and Scherbaum, Frank},
  title     = {The impact of the spatial uniform distribution of seismicity on probabilistic seismic-hazard estimation},
  series = {Bulletin of the Seismological Society of America},
  volume    = {96},
  journal   = {Bulletin of the Seismological Society of America},
  number    = {6},
  publisher = {GeoScienceWorld},
  address   = {Alexandria, Va.},
  issn      = {0037-1106},
  doi       = {10.1785/0120060073},
  pages     = {2465 -- 2471},
  year      = {2006},
  abstract  = {The first step in the estimation of probabilistic seismic hazard in a region commonly consists of the definition and characterization of the relevant seismic sources. Because in low-seismicity regions seismicity is often rather diffuse and faults are difficult to identify, large areal source zones are mostly used. The corresponding hypothesis is that seismicity is uniformly distributed inside each areal seismic source zone. In this study, the impact of this hypothesis on the probabilistic hazard estimation is quantified through the generation of synthetic spatial seismicity distributions. Fractal seismicity distributions are generated inside a given source zone and probabilistic hazard is computed for a set of sites located inside this zone. In our study, the impact of the spatial seismicity distribution is defined as the deviation from the hazard value obtained for a spatially uniform seismicity distribution. From the generation of a large number of synthetic distributions, the correlation between the fractal dimension D and the impact is derived. The results show that the assumption of spatially uniform seismicity tends to bias the hazard to higher values. The correlation can be used to determine the systematic biases and uncertainties for hazard estimations in real cases, where the fractal dimension has been determined. We apply the technique in Germany (Cologne area) and in France (Alps).},
  language  = {en}
}
@article{BeauvalHainzlScherbaum2006,
  author    = {Beauval, C{\´e}line and Hainzl, Sebastian and Scherbaum, Frank},
  title     = {Probabilistic seismic hazard estimation in low-seismicity regions considering non-Poissonian seismic occurrence},
  issn      = {0956-540X},
  doi       = {10.1111/j.1365-246X.2006.02863.x},
  year      = {2006},
  abstract  = {In low-seismicity regions, such as France or Germany, the estimation of probabilistic seismic hazard must cope with the difficult identification of active faults and with the low amount of seismic data available. Since the probabilistic hazard method was initiated, most studies assume a Poissonian occurrence of earthquakes. Here we propose a method that enables the inclusion of time and space dependences between earthquakes into the probabilistic estimation of hazard. Combining the seismicity model Epidemic Type Aftershocks-Sequence (ETAS) with a Monte Carlo technique, aftershocks are naturally accounted for in the hazard determination. The method is applied to the Pyrenees region in Southern France. The impact on hazard of declustering and of the usual assumption that earthquakes occur according to a Poisson process is quantified, showing that aftershocks contribute on average less than 5 per cent to the probabilistic hazard, with an upper bound around 18 per cent},
  language  = {en}
}
@article{HainzlZoellerMain2006,
  author    = {Hainzl, Sebastian and Z{\"o}ller, Gert and Main, Ian},
  title     = {Introduction to special issue: Dynamics of seismicity patterns and earthquake triggering - Preface},
  series = {Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth},
  volume    = {424},
  journal   = {Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth},
  number    = {Special issue},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0040-1951},
  doi       = {10.1016/j.tecto.2006.03.034},
  pages     = {135 -- 138},
  year      = {2006},
  language  = {en}
}
@article{HainzlScherbaumBeauval2006,
  author    = {Hainzl, Sebastian and Scherbaum, Frank and Beauval, C{\´e}line},
  title     = {Estimating background activity based on interevent-time distribution},
  issn      = {0037-1106},
  doi       = {10.1785/0120050053},
  year      = {2006},
  abstract  = {The statistics of time delays between successive earthquakes has recently been claimed to be universal and to show the existence of clustering beyond the duration of aftershock bursts. We demonstrate that these claims are unjustified. Stochastic simulations with Poissonian background activity and triggered Omori-type aftershock sequences are shown to reproduce the interevent-time distributions observed on different spatial and magnitude scales in California. Thus the empirical distribution can be explained without any additional long-term clustering. Furthermore, we find that the shape of the interevent-time distribution, which can be approximated by the gamma distribution, is determined by the percentage of main-shocks in the catalog. This percentage can be calculated by the mean and variance of the interevent times and varies between 5\% and 90\% for different regions in California. Our investigation of stochastic simulations indicates that the interevent-time distribution provides a nonparametric reconstruction of the mainshock magnitude-frequency distribution that is superior to standard declustering algorithm},
  language  = {en}
}