Bayesian inference of earthquake source parameters: kinematic and dynamic finite fault models

震源参数的贝叶斯推断：运动学和动力有限断层模型

• 批准号: 391058966
• 负责人: Dr. Alice-Agnes Gabriel
• 金额: --
• 依托单位: Sektion Geophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/391058966?language=en
• 关键词: Bayesian; inference; earthquake; source; parameters

Proper understanding of geophysical processes controlling earthquake rupture propagation is a key point in earthquake hazard mitigation. Slip inversions provide details on rupture propagation by modeling seismic records. However, they are inherently non-unique requiring regularization and typically lacking proper uncertainty estimation. We aim at i) utilizing dynamic rupture modeling to regularize the solution and ii) use a Bayesian approach to capture correctly the uncertainty of the retrieved parameters. To further improve our knowledge about the physical processes affecting the rupture, we will extend the models from finite source inversions to more realistic conditions utilizing the SeisSol software package. This enhanced approach will be applied primarily to selected M~6 events with distinct behaviors in their rupture propagation that are challenging to explain in terms of rheological complexity (segment jumps, large shallow slip, on-fault frictional barriers), and possibly also to a few well-recorded significant (M>6) earthquakes that would occur worldwide during the research period. The proposed research will require the development of new codes for mathematical modeling of the earthquake fault rupture process, modification of existing frameworks and utilization of high-performance computing infrastructure. For the development of kinematic and dynamic slip inversions in the Bayesian framework we will extend kinematic earthquake source inversion codes of the Charles University in Prague (CUP) and develop new ones for dynamic source inversions. To constrain earthquake source processes from observations, we will extend the inferred earthquake source models to large-scale (high-resolution) dynamic rupture scenarios of selected real events. To this aim, we will utilize the SeisSol software package developed at the Ludwig-Maximilians-University Munich (LMU) which allows to incorporate complex, natural fault zones. This proposal for bilateral funding aims to complement expertise of two young researchers in earthquake source physics and ground motion modeling. Combination of expertise of the researchers of the two groups will permit to go beyond standard kinematic source inversions and beyond scenario-based forward dynamic rupture simulations towards the development of fully dynamic finite-extent source models, to perform physically consistent, finite-extent source inversions including evaluation of parameter uncertainties by means of Bayesian inference. The newly developed codes, combining cutting-edge methods for solving the forward and inverse problem, will make use of modern and future high-performance computing infrastructure and will be made fully available to the seismological community worldwide.

正确认识控制地震破裂传播的地球物理过程是减轻地震灾害的关键。滑动反演通过模拟地震记录提供了破裂传播的细节。然而，它们本质上是非唯一的，需要正则化，并且通常缺乏适当的不确定性估计。我们的目标是i）利用动态破裂模型来正则化的解决方案和ii）使用贝叶斯方法来正确捕捉检索参数的不确定性。为了进一步提高我们的知识，影响破裂的物理过程，我们将扩展模型从有限源反演到更现实的条件下，利用SeisSol软件包。这种改进的方法将主要应用于选定的M~6事件，这些事件在破裂传播中具有独特的行为，这些行为在流变学复杂性方面具有挑战性（段跳跃，大型浅层滑动，断层上的摩擦障碍），并且可能也适用于研究期间全球范围内发生的少数有记录的重大（M>6）地震。拟议的研究将需要开发新的地震断层破裂过程的数学建模代码，修改现有的框架和利用高性能的计算基础设施。为了在贝叶斯框架中发展运动学和动力学滑动反演，我们将扩展布拉格查尔斯大学（CUP）的运动学震源反演代码，并开发新的动力学震源反演代码。 为了从观测中约束震源过程，我们将把推断的震源模型扩展到选定的真实的事件的大尺度（高分辨率）动态破裂情景。为此，我们将利用路德维希-马克西米利安慕尼黑大学（LMU）开发的SeisSol软件包，该软件包允许合并复杂的自然断层带。这项双边资助建议旨在补充两名年轻研究人员在震源物理学和地面运动建模方面的专门知识。这两个小组的研究人员的专业知识相结合，将允许超越标准的运动学源反演和超越基于正演的动态破裂模拟，以发展完全动态的有限范围源模型，进行物理上一致的，有限范围的源反演，包括通过贝叶斯推理评估参数的不确定性。新开发的代码结合了解决正问题和反问题的尖端方法，将利用现代和未来的高性能计算基础设施，并将完全提供给世界各地的地震界。