Comparison of deterministic and stochastic earthquake simulators for fault interactions in the Lower Rhine Embayment, Germany
Comparison of deterministic and stochastic earthquake simulators for fault interactions in the Lower Rhine Embayment, Germany
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DOI：
10.1093/gji/ggt271
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发表时间：
2013-04
影响因子：
2.8
通讯作者：
S. Hainzl;G. Zöller;G. Brietzke;K. Hinzen
中科院分区：
文献类型：
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作者：
S. Hainzl;G. Zöller;G. Brietzke;K. Hinzen
时变概率地震危险性评估需要对地震发生进行随机描述。虽然短期地震活动性模型受到观测的良好约束，但特征性断层地震的重现性仅来自理论考虑、不确定的古事件或代用数据。尽管所涉及的不确定性和复杂性，简单的统计模型的准周期复发的故障事件实施的地震危险性评估。为了测试统计模型的适用性，如布朗弛豫振荡器或应力释放模型，我们进行了系统的比较与确定性模拟的基础上速率和状态相关的摩擦，高分辨率表示故障系统和准动态破裂传播。对于特定的故障网络的下莱茵河Embayment，德国，我们运行随机和确定性模型模拟相同的故障几何形状和应力相互作用的基础上。我们的研究结果表明，随机模拟器能够再现一阶特征的大地震的孤立故障，以及耦合故障与中等应力相互作用。然而，我们发现，所有测试的统计模型未能再现强耦合故障的特性，因为多段破裂造成的时空相关的应力场被低估的随机模拟器。我们的研究结果表明，随机模型必须扩展多破裂概率分布，以提供更可靠的结果。
Time-dependent probabilistic seismic hazard assessment requires a stochastic description of earthquake occurrences. While short-term seismicity models are well-constrained by observations, the recurrences of characteristic on-fault earthquakes are only derived from theoretical considerations, uncertain palaeo-events or proxy data. Despite the involved uncertainties and complexity, simple statistical models for a quasi-period recurrence of on-fault events are implemented in seismic hazard assessments. To test the applicability of statistical models, such as the Brownian relaxation oscillator or the stress release model, we perform a systematic comparison with deterministic simulations based on rate- and state-dependent friction, high-resolution representations of fault systems and quasi-dynamic rupture propagation. For the specific fault network of the Lower Rhine Embayment, Germany, we run both stochastic and deterministic model simulations based on the same fault geometries and stress interactions. Our results indicate that the stochastic simulators are able to reproduce the first-order characteristics of the major earthquakes on isolated faults as well as for coupled faults with moderate stress interactions. However, we find that all tested statistical models fail to reproduce the characteristics of strongly coupled faults, because multisegment rupturing resulting from a spatiotemporally correlated stress field is underestimated in the stochastic simulators. Our results suggest that stochastic models have to be extended by multirupture probability distributions to provide more reliable results.