Recurrent Large Earthquakes in a Fault Region: What Can Be Inferred from Small and Intermediate Events?
Recurrent Large Earthquakes in a Fault Region: What Can Be Inferred from Small and Intermediate Events?
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断层区经常发生的大地震：从中小型和中型事件可以推断出什么？
DOI：
10.1785/0120080146
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发表时间：
2008
影响因子：
3
通讯作者：
M. Holschneider
中科院分区：
文献类型：
--
作者：
G. Zöller;S. Hainzl;M. Holschneider
我们提出了一个更新模型的大地震的复发断层带组成的一个主要故障和周围的小故障与古腾堡-里希特型地震活动表示的地震矩释放从截断幂律分布。探讨了主断裂特征地震的复发时间。它不断加载（板块运动），并由于相邻的较小断层而经历正负波动，在两次大地震之间有大量的N eq这种变化。由于分布具有有限的方差，在极限N eq→∞中，中心极限定理意味着递归时间遵循布朗时间（BPT）分布。这使我们能够计算个别的复发时间分布为特定的断层带，而无需调整自由参数：平均复发时间可以估计从地质或古地震数据，和标准偏差是确定的频率大小分布，即里氏B值，地震目录。该方法被证明是在加州的圣安德烈亚斯断层的帕克菲尔德段，以及一个数值断层模型的长期模拟。假设幂律分布的地震震级的大小经常性的帕克菲尔德事件（M6），我们发现一个变异系数，高于通过直接拟合的BPT分布7个大地震得到的值。我们认为，BPT分布是一个合理的选择，地震危险性评估，因为它不仅管理布朗运动漂移，但也与幂律统计模型的大地震复发的渐近极限。最后，我们发现条件B =1将两个区域分开：在第一个区域（B 1）中，它更大。
We present a renewal model for the recurrence of large earthquakes in a fault zone consisting of a major fault and surrounding smaller faults with Gutenberg–Richter-type seismicity represented by seismic moment release drawn from a truncated power-law distribution. The recurrence times of characteristic earthquakes for the major fault are explored. It is continuously loaded (plate motion) and undergoes positive and negative fluctuations due to adjacent smaller faults, with a large number N eq of such changes between two major earthquakes. Because the distribution has a finite variance, in the limit N eq→∞ the central limit theorem implies that the recurrence times follow a Brownian passage-time (BPT) distribution. This allows us to calculate individual recurrence-time distributions for specific fault zones without tuning free parameters: the mean recurrence time can be estimated from geological or paleoseismic data, and the standard deviation is determined from the frequency-size distribution, namely, the Richter b -value, of an earthquake catalog. The approach is demonstrated for the Parkfield segment of the San Andreas fault in California as well as for a long simulation of a numerical fault model. Assuming power-law distributed earthquake magnitudes up to the size of the recurrent Parkfield event ( M 6), we find a coefficient of variation that is higher than the value obtained by a direct fit of the BPT distribution to seven large earthquakes. We argue that the BPT distribution is a reasonable choice for seismic hazard assessment because it governs not only Brownian motion with drift but also models with power-law statistics for the recurrence of large earthquakes in an asymptotic limit. Finally, we find that the condition b =1 separates two regimes: in the first ( b 1) it is greater.