权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Comprehensive study for statistical prediction of seismic activity

地震活动统计预测综合研究

基本信息

批准号：
14380128
负责人：
OGATA Yosihiko
金额：
$ 5.31万
依托单位：
The Institute of Statistical Mathematics
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

One important outcome emerging from this study is the use of statistical models as diagnostic tools to identify anomalous trends and other features of the seismicity pattern. The ETAS model itself is an extremely useful tool in detecting anomalous features in seismic activity, including aftershock activity, and in identifying and defining seismic quiescence. The results of comparing the actual seismicity rates with the rates predicted by the ETAS model have very interesting implications for the physical interpretation of the processes controlling the evolution of seismicity. The connections between seismicity rate changes and coseismic stress changes have been emphasized and discussed in several important recent publications. In particular, it is worth noting that the relative quiescence defined in relation to the ETAS model represents the best currently available definition and physical interpretation of the "stress shadow". In other words, this represents the most robust definition t … More he stress shadow and the proposed numerical approach is the best solution to identify seismicity rate reductions. This has been recognized by the scientific community.We have proposed the Hierarchical Space-Time ETAS model that is extended for applying space-time coordinates of earthquake catalogs. Regional earthquake occurrence rate is modeled as a function of previous activity whose specific form is based on empirical laws such as the modified Omori formula and the Utsu-Seki scaling law of aftershock area against magnitude. Its parameters, including the p-value of the aftershock decay rate, can vary from place to place. This model is used to visualize features of the regional seismic activities in and around Japan. Among the five parameters of the model, the spatial variation of the K-parameter (the productivity of aftershocks) can be well correlated with asperity locations. Furthermore, the model enables us to enhance the regions where the actual occurrence rates deviate systematically from the modeled one. In particular, the relative quiescence or the seismic gap of the second type is of great concern. Also, the incidental outcomes of our research include the stochastc clustering / declustering procedure by the space-time ETAS model, which enables another diagnostic tool to examine the adequacy of a space-time model when we are given a dataset. Less

这项研究的一个重要成果是使用统计模型作为诊断工具，以确定地震活动模式的异常趋势和其他特征。ETAS模型本身是一个非常有用的工具，可以用来探测地震活动的异常特征，包括余震活动，以及识别和定义地震平静。将实际地震活动速率与ETAS模型预测的地震活动速率进行比较的结果，对于控制地震活动演化的过程的物理解释具有非常有趣的意义。地震活动速率变化和同震应力变化之间的关系在最近的几个重要出版物中得到了强调和讨论。尤其值得注意的是，相对于ETAS模型定义的相对静止代表了目前对“应力阴影”的最佳定义和物理解释。换句话说，这代表了…最健壮的定义强调阴影，提出的数值方法是识别地震活动性减少率的最好方法。这一点已经得到科学界的认可。我们提出了层次化的时空ETAS模型，该模型被扩展应用于地震目录的时空坐标。区域地震发生率被模拟为先前活动的函数，其具体形式是基于经验定律，如修正的Omori公式和余震面积对震级的Utsu-Seki标度定律。它的参数，包括余震衰减率的p值，可能会因地而异。该模型用于可视化日本境内及周边地区的地震活动特征。在模型的5个参数中，K参数(余震生产力)的空间变化与粗糙度位置有很好的相关性。此外，该模型使我们能够增强实际发生率系统地偏离模型的区域。尤其是第二种类型的相对静止或地震空区是非常令人关注的。此外，我们研究的附带结果包括时空ETAS模型的stochastc聚类/去聚过程，这使得另一种诊断工具能够在我们给定数据集时检查时空模型的充分性。较少