Using a dynamic earthquake simulator to investigate controls on slow-slip events, subduction earthquakes, and their interactions

使用动态地震模拟器研究慢滑移事件、俯冲地震及其相互作用的控制

基本信息

批准号：
2147340
负责人：
Benchun Duan
金额：
$ 44.65万
依托单位：
Texas A&M University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-06-01 至 2025-05-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2147340&HistoricalAwards=false
关键词：
Using dynamic earthquake simulator investigate

项目摘要

Advanced geodetic and seismic instrumentations during the past two decades have revealed various slip behaviors along subduction zones. In addition to large earthquakes with slip of up to tens of meters over seconds to minutes that cause strong ground shaking and/or damaging tsunami along coastal areas, slow-slip events occur quietly with a few to tens of centimeters of slip over days to years that can only be detected by sensitive instruments. Observations show complex interactions between slow-slip events and subduction earthquakes. What factors and processes controls these different slip behaviors and their interactions along subduction zones? Physics-based numerical models are arguably the most useful tool to address this problem. Previous models have been largely built separately for either slow-slip events or large earthquakes along subduction zones, limiting their abilities to explore the interactions of the two. In this project, the researchers will use and further develop a dynamic earthquake simulator to quantify physical factors and processes that control slow-slip events, subduction earthquakes and their interactions in one unified framework. This research will advance our physical understanding of observed features in the two phenomena and their interactions. As slow-slip events occur more frequently, improved understanding of these events and their roles in the occurrence of large earthquakes can be directly used to assess future seismic and tsunami hazards along subduction zones worldwide, including the Cascadia and Alaska subduction zones. High-performance computing systems will be intensively used in this project, advancing their usage in natural hazards research and reduction. This research will set a stage for future efforts to assimilate available geodetic and seismic observations to develop region-specific, physics-based models for seismic and tsunami hazards analysis and mitigation. The project will train future scientists to pursue these efforts.This research is to use physics-based models to explore physical factors and processes that control slow-slip events, subduction earthquakes and their interactions. The investigators will use and further develop a dynamic earthquake simulator that can capture both spontaneously dynamic rupture propagation and other quasi-static processes of earthquakes cycles, including nucleation, postseismic and interseismic processes. The dynamic earthquake simulator is based on a finite element method and thus can handle geometrically complex faults in heterogeneous geologic media, including shallowly dipping subduction interfaces with subducted seafloor features. Slow-slip events and subduction earthquakes will emerge spontaneously over multiple earthquake cycles and can be captured accurately in our multicycle dynamic models. Therefore, physical factors and processes that control slow-slip events generation and characteristics, subduction earthquakes generation and their interactions can be quantified. The investigators plan to select the northern Hikurangi margin as the focus area of this research. They will also explore the southern Hikurangi margin and the Japan trench at the later stage of the project. By reproducing observed features of slow-slip events, historical earthquakes, and their interactions in the selected case studies, the investigators will quantify factors and processes that dominate these different slip behaviors and their complex interactions. Findings from this research can be used to assess seismic and tsunami hazards along subduction zones worldwide.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在过去的二十年中，先进的地震仪和地震仪器沿俯冲带揭示了各种滑动行为。除了在几秒钟到几分钟内滑落到数十米的大地震外，会导致地面摇晃和/或在沿海地区破坏海啸，慢滑行事件悄然发生，几天到几年，几天到几十厘米只能通过敏感仪器检测到。观测表明，慢滑行事件与俯冲地震之间的复杂相互作用。哪些因素和过程控制着这些不同的滑移行为及其沿俯冲区域的相互作用？基于物理的数值模型可以说是解决此问题的最有用的工具。以前的模型主要是针对慢速事件或沿俯冲带的大地震而单独构建的，从而限制了它们探索两者相互作用的能力。在这个项目中，研究人员将使用并进一步开发动态的地震模拟器来量化控制慢滑行事件，俯冲地震及其相互作用的物理因素和过程。这项研究将提高我们对两种现象及其相互作用中观察到的特征的物理理解。随着慢滑行事件发生频率更高，人们对这些事件的了解及其在发生大地震发生的作用的改善，可以直接用于评估全球俯冲带（包括卡斯卡迪亚和阿拉斯加俯冲Zones）的未来地震和海啸危害。高性能计算系统将在该项目中进行大量使用，从而推进其在自然危害研究和减少中的用途。这项研究将为未来的努力设定一个阶段，以吸收可用的地震和地震观测，以开发针对地震和海啸危害分析和缓解的基于区域的，基于物理的模型。该项目将培训未来的科学家追求这些努力。这项研究是使用基于物理的模型来探索控制慢速事件，俯冲地震及其相互作用的物理因素和过程。研究人员将使用并进一步开发动态地震模拟器，该模拟器可以捕获自发动态破裂的传播和其他地震周期的准静态过程，包括成核，后观察和瞬变过程。动态地震模拟器基于有限的元素方法，因此可以处理异质地质介质中的几何复杂断层，包括具有俯冲海底特征的浅倾角俯冲接口。慢速事件和俯冲地震将自发出现在多个地震周期上，并且可以在我们的多环动力学模型中准确捕获。因此，可以量化控制慢速事件的产生和特征，俯冲地震产生及其相互作用的物理因素和过程。调查人员计划选择北部的Hikurangi利润率作为这项研究的重点领域。他们还将在该项目的后期探索南部的Hikurangi利润和日本沟渠。通过重现慢滑行事件，历史地震及其在所选案例研究中的相互作用的观察到的特征，研究人员将量化主导这些不同的滑移行为及其复杂相互作用的因素和过程。这项研究的结果可用于评估全球俯冲区域沿俯冲区域的地震和海啸危害。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响评估标准，认为值得通过评估来获得支持。