Collaborative Research: Multi-scale models of subduction zone earthquake cycle observations

合作研究：俯冲带地震周期观测的多尺度模型

• 批准号: 1722680
• 负责人: Thorsten Becker
• 金额: $ 23.35万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1722680&HistoricalAwards=false
• 关键词: Collaborative; Research; Multi; scale; models

Earth's tectonic plates get recycled back into the mantle at subduction zones. The largest earthquakes happen there, and these megathrust environments also generate a range of other geohazards including tsunamis and volcanoes, making their study of great societal relevance. Recently, seismological and geodetic measurements have revealed a range of phenomena associated with megathrust behavior that are not captured by a simple, stick-slip earthquake cycle model of slow loading and catastrophic rupture. These newly discovered phenomena include transient, creeping events of fault slip on decadal scales which may indicate preparatory behavior of the fault system, perhaps systematically linked to the main seismic event. Mechanical models have not quite kept up with these new discoveries and our understanding of the physical processes behind these phenomena is incomplete. A new, integrative framework is therefore needed to understand the physical mechanisms and fault constitutive laws behind complex deformation and seismicity patterns. This project seeks to develop such a mechanical model, initially for the data rich Japan setting, in order to understand regional megathrust dynamics and fault interaction patterns, as well as improve seismic hazard estimates. Later, such a mechanical model may potentially be deployed at other subduction zones such as Cascadia and assist in interpreting existing and planned monitoring data streams for earthquake forecasting and early warning. To capture the spatial and temporal scales involved in this complex problem, three sub-projects are to be pursued in collaboration between researchers at University of Texas Austin (UTIG), Purdue University, and the University of Tokyo: 1) The development of sets of multi earthquake-cycle scenarios based on numerical models of visco-elastic, inter-, pre-, co- and post-seismic fault loading in Japan. 2) The development of global mantle flow and regional, time-evolving mantle convection models to understand long-term, subduction induced forcing of plate boundaries and backarcs in the region. 3) The development of cross-timescale, visco-elasto-plastic models in 3-D, incorporating rate and state friction as well as other fault constitutive laws in a dynamically consistent, thermo-mechanical convection framework. This will enable, for example, studying the role of pre-seismic, slow slip phenomena for fault zone evolution, eventually in the presence of fluid flow. All project parts will be integrated, and results from different approaches cross-checked. Moreover, all sub-projects are complementary and will guide the establishment of the general subduction zone model that is needed to understand earthquake cycle observations and seismicity in Japan and elsewhere.

地球的构造板块会在俯冲带再循环回到地幔中。最大的地震发生在那里，这些巨型逆冲环境也产生了一系列其他地质灾害，包括海啸和火山，使他们的研究具有重大的社会意义。最近，地震学和大地测量揭示了一系列与巨型逆冲断层行为相关的现象，这些现象不能被一个简单的缓慢加载和灾难性破裂的粘滑地震周期模型所捕获。这些新发现的现象包括在十年尺度上的断层滑动的瞬态蠕动事件，这可能表明断层系统的预备行为，可能与主要地震事件有系统的联系。力学模型还没有完全跟上这些新发现，我们对这些现象背后的物理过程的理解是不完整的。因此，需要一个新的综合框架来理解复杂变形和地震活动模式背后的物理机制和断层本构律。该项目旨在开发这样一个力学模型，最初用于数据丰富的日本环境，以了解区域巨型逆冲断层动力学和断层相互作用模式，以及改善地震危险性估计。之后，这种力学模型可能会部署在其他俯冲带，如卡斯卡迪亚，并协助解释现有的和计划的监测数据流，用于地震预报和预警。为了捕捉这一复杂问题所涉及的空间和时间尺度，德克萨斯大学奥斯汀分校（UTIG），普渡大学和东京大学的研究人员将合作开展三个子项目：1）基于日本粘弹性，地震间，地震前，地震同震和地震后断层加载的数值模型，开发多地震周期情景。2)发展全球地幔流和区域性的、随时间演变的地幔对流模型，以了解该地区板块边界和后弧的长期俯冲诱导作用力。3)跨时间尺度的发展，粘弹塑性模型在3-D，纳入率和状态摩擦，以及其他故障本构关系的动态一致，热机械对流框架。这将使，例如，研究地震前的作用，缓慢滑动现象的断层带演化，最终在流体流动的存在。项目的所有部分将被整合，不同方法的结果将被交叉检查。此外，所有分项目都是相辅相成的，将指导建立一般俯冲带模型，这是了解日本和其他地方地震周期观测和地震活动所需要的。

项目成果

Stress change before and after the 2011 M9 Tohoku-oki earthquake

• DOI: 10.1016/j.epsl.2018.09.035
• 发表时间: 2018-12-15
• 期刊: EARTH AND PLANETARY SCIENCE LETTERS
• 影响因子: 5.3
• 作者: Becker, Thorsten W.;Hashima, Akinori;Sato, Hiroshi
• 通讯作者: Sato, Hiroshi

Sediment control on subduction plate speeds

• DOI: 10.1016/j.epsl.2018.08.057
• 发表时间: 2018-11
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: W. Behr;T. Becker

Simulation of slip transients and earthquakes in finite thickness shear zones with a plastic formulation.

• DOI: 10.1038/s41467-018-06390-z
• 发表时间: 2018-09-25
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Tong X;Lavier LL
• 通讯作者: Lavier LL

416-PFLOPS fast scalable implicit solver on low-ordered unstructured finite elements accelerated by 1.10-ExaFLOPS kernel with reformulated AI-like algorithm: For equation-based earthquake modeling

低阶非结构化有限元上的 416-PFLOPS 快速可扩展隐式求解器由 1.10-ExaFLOPS 内核加速，并采用重新制定的类 AI 算法：用于基于方程的地震建模

• 发表时间: 2019
• 期刊: Storage and Analysis.
• 作者: IIchimura, T.