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Statistical analysis of time-dependent earthquake occurrence and its impact on hazard in the low seismicity region Lower Rhine Embayment 总被引：1，自引：0，他引：1
Licia Faenza Sebastian Hainzl Frank Scherbaum Céline Beauval 《Geophysical Journal International》2007,171(2):797-806
The time-dependence of earthquake occurrence is mostly ignored in standard seismic hazard assessment even though earthquake clustering is well known. In this work, we attempt to quantify the impact of more realistic dynamics on the seismic hazard estimations. We include the time and space dependences between earthquakes into the hazard analysis via Monte Carlo simulations. Our target region is the Lower Rhine Embayment, a low seismicity area in Germany. Including aftershock sequences by using the epidemic type aftershock-sequence (ETAS) model, we find that on average the hypothesis of uncorrelated random earthquake activity underestimates the hazard by 5–10 per cent. Furthermore, we show that aftershock activity of past large earthquakes can locally increase the hazard even centuries later. We also analyse the impact of the so-called long-term behaviour, assuming a quasi-periodic occurrence of main events on a major fault in that region. We found that a significant impact on hazard is only expected for the special case of a very regular recurrence of the main shocks. 相似文献
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Earthquake swarms are often assumed to be caused by magmatic or fluid intrusions, where the stress changes in the vicinity
of the intrusion control the position, strength and rate of seismicity. Fracture mechanical models of natural intrusions or
man-made hydrofractures pose constraints on orientation, magnitude, shape and growing rate of fractures and can be used to
estimate stress changes in the vicinity of the intrusions. Although the idea of intrusion-induced seismicity is widely accepted,
specific comparisons of seismicity patterns with fracture models of stress changes are rarely done.
The goal of the study is to review patterns of intrusion-induced earthquake swarms in comparison to the observations of the
swarm in NW Bohemia in 2000. We analyse and discuss the theoretical 3D shape of intrusions under mixed mode loading and apparent
buoyancy. The aspect ratio and form of the intrusion is used to constrain parameters of the fluid, the surrounding rock and
stress. We conclude that the 2000 NW Bohemia swarm could have been driven by a magmatic intrusion. The intrusion was, however,
inclined to the maximal principal stress and caused shear displacement additional to opening. We estimate that the density
diference between magma and rock was small. The feeding reservoir was possibly much larger than the area affected from earthquakes
and may be a vertical dike beneath the swarm region. 相似文献
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Seismicity patterns of earthquake swarms due to fluid intrusion and stress triggering 总被引：10，自引：0，他引：10
Sebastian Hainzl 《Geophysical Journal International》2004,159(3):1090-1096
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Esther Hintersberger Frank Scherbaum Sebastian Hainzl 《Bulletin of Earthquake Engineering》2007,5(1):1-16
Scherbaum et al. [(2004) Bull Seismolo Soc Am 94(6): 2164–2185] proposed a likelihood-based approach to select and rank ground-motion
models for seismic hazard analysis in regions of low-seismicity. The results of their analysis were first used within the
PEGASOS project [Abrahamson et al. (2002), In Proceedings of the 12 ECEE, London, 2002, Paper no. 633] so far the only application
of a probabilistic seismic hazard analysis (PSHA) in Europe which was based on a SSHAC Level 4 procedure [(Budnitz et al.
1997, Recommendations for PSHA: guidance on uncertainty and use of experts. No. NUREG/CR-6372-V1). The outcome of this project
have generated considerable discussion (Klügel 2005, Eng Geol 78:285–307, 2005b) Eng Geol 78: 285–307, (2005c) Eng Geol 82:
79–85 Musson et al. (2005) Eng Geol 82(1): 43–55]; Budnitz et al. (2005), Eng Geol 78(3–4): 285–307], a central part of which
is related to the issue of ground-motion model selection and ranking. Since at the time of the study by Scherbaum et al. [(2004.)
Bull Seismolo Soc Am 94(6): 2164–2185], only records from one earthquake were available for the study area, here we test the
stability of their results using more recent data. Increasing the data set from 12 records of one earthquake in Scherbaum
et al. [(2004) Bull Seismolo Soc Am 94(6): 2164–2185] to 61 records of 5 earthquakes, which have mainly occurred since the
publication of the original study, does not change the set of the three top-ranked ground-motion models [Abrahamson and Silva
(1997) Seismolo Res Latt 68(1): 94–127; Lussou et al. (2001) J Earthquake Eng 5(1):13–33; Berge-Thierry et al. (2003) Bull
Seismolog Soc Am 95(2): 377–389. Only for the lower-ranked models do we obtain modifications in the ranking order. Furthermore,
the records from the Waldkirch earthquake (Dec, 5th, 2004, M
w = 4.9) enabled us to develop a new stochastic model parameter set for the application of Campbell’s [(2003) Bull Seismolo
Soc Am 93(3): 1012–1033] hybrid empirical model to SW Germany and neighbouring regions. 相似文献
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T. Dahm D. Becker M. Bischoff S. Cesca B. Dost R. Fritschen S. Hainzl C. D. Klose D. K��hn S. Lasocki Th. Meier M. Ohrnberger E. Rivalta U. Wegler Stephan Husen 《Journal of Seismology》2013,17(1):197-202
Various techniques are utilized by the seismological community, extractive industries, energy and geoengineering companies to identify earthquake nucleation processes in close proximity to engineering operation points. These operations may comprise fluid extraction or injections, artificial water reservoir impoundments, open pit and deep mining, deep geothermal power generations or carbon sequestration. In this letter to the editor, we outline several lines of investigation that we suggest to follow to address the discrimination problem between natural seismicity and seismic events induced or triggered by geoengineering activities. These suggestions have been developed by a group of experts during several meetings and workshops, and we feel that their publication as a summary report is helpful for the geoscientific community. Specific investigation procedures and discrimination approaches, on which our recommendations are based, are also published in this Special Issue (SI) of Journal of Seismology. 相似文献
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We present a Bayesian method that allows continuous updating the aperiodicity of the recurrence time distribution of large earthquakes based on a catalog with magnitudes above a completeness threshold. The approach uses a recently proposed renewal model for seismicity and allows the inclusion of magnitude uncertainties in a straightforward manner. Errors accounting for grouped magnitudes and random errors are studied and discussed. The results indicate that a stable and realistic value of the aperiodicity can be predicted in an early state of seismicity evolution, even though only a small number of large earthquakes has occurred to date. Furthermore, we demonstrate that magnitude uncertainties can drastically influence the results and can therefore not be neglected. We show how to correct for the bias caused by magnitude errors. For the region of Parkfield we find that the aperiodicity, or the coefficient of variation, is clearly higher than in studies which are solely based on the large earthquakes. 相似文献
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