Toward Exascale Global Adjoint Tomography

迈向百亿亿次全球伴随断层扫描

• 批准号: 1644826
• 负责人: Jeroen Tromp
• 金额: $ 54.75万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1644826&HistoricalAwards=false
• 关键词: Toward; Exascale; Global; Adjoint; Tomography

This research involves the development of open-source software for simulations of seismic wave propagation inside the Earth. Such simulations may be used for quantitative seismic hazard assessment, visualizations for outreach and educational activities, as well as a basis for seismic tomography. Like medical tomography, the goal of seismic tomography is to image the Earth's interior on all scales, from hydrocarbon fields in exploration seismology to Earth's mantle in global seismology, to help us understand our planet's inner workings and evolution. As a broader impact this project will publish earthquake wave animations online in near real-time for events with magnitudes of 5.5 and greater at Princeton University's Near Real Time Seismicity Portal (GlobalShakeMovie) .The main goal of this research is to further develop global seismic tomography using complete seismic waveforms and adjoint-state methods by enabling massive data assimilation and harnessing the largest and fastest available computers. Using a pilot dataset of 253 earthquakes, a first-generation global tomographic model based on "adjoint tomography", an iterative full-waveform inversion technique was built. Based on this experience, a next-generation global model will be constructed by assimilating full waveform data from thousands of earthquakes that were well recorded by broadband global and regional seismographic networks. Prior NSF support demonstrated the feasibility of regional adjoint tomography for isotropic heterogeneity, anelasticity, and azimuthal anisotropy. Similar inversions on a global scale will be done through secured access to the necessary computational hardware through the Department of Energy INCITE program. This research supports a portion of the required human resources, where the rate-limiting steps in this ambitious endeavor are data quality control, I/O, and workflow management. Four main tasks will be tackled bearing these obstacles in mind: 1) prepare and further develop the open source spectral-element seismic wave propagation solvers SPECFEM3D and SPECFEM3D_GLOBE for exascale simulations; 2) further develop the Adaptable Seismic Data Format (ASDF) for fast I/O; 3) further develop the inversion & migration toolkit SeisFlows by taking advantage of the open source Structured Query Language database engine SQLight and existing workflow management tools, such as Pegasus; and 4) perform global adjoint seismic tomography with a database of thousands of earthquakes at a shortest period of 9 s. Task 4 encompasses the main goal of the proposal, but it cannot be completed without simultaneously addressing the other tasks.

这项研究涉及开发用于模拟地震波在地球内部传播的开放源码软件。这种模拟可用于定量地震危险评估、宣传和教育活动的可视化，以及地震层析成像的基础。与医学断层扫描一样，地震断层扫描的目标是在所有尺度上对地球内部进行成像，从勘探地震学中的碳氢化合物领域到全球地震学中的地幔，以帮助我们了解地球的内部运作和演变。作为更广泛的影响，该项目将在普林斯顿大学的近真实的地震活动门户（GlobalShakeMovie）上以近实时的方式在线发布5.5级及以上事件的地震波动画。这项研究的主要目标是通过实现大规模数据同化和利用最大、最快的计算机，使用完整的地震波形和伴随状态方法进一步开发全球地震层析成像。利用253个地震的试验数据集，建立了基于“伴随层析成像”的第一代全球层析成像模型，并提出了一种迭代全波形反演技术。根据这一经验，将通过吸收宽带全球和区域地震台网充分记录的数千次地震的全波形数据，构建下一代全球模型。先前NSF的支持证明了区域伴随层析成像对各向同性异质性、滞弹性和方位各向异性的可行性。全球范围内的类似反演将通过能源部INCITE计划安全访问必要的计算硬件来完成。这项研究支持所需的人力资源的一部分，在这一雄心勃勃的奋进中的限速步骤是数据质量控制，I/O和工作流管理。考虑到这些障碍，将处理四项主要任务：1）准备和进一步开发用于兆尺度模拟的开放源谱元地震波传播解算器SPECFEM 3D和SPECFEM3D_GLOBE; 2）进一步开发用于快速I/O的自适应地震数据格式（ASDF）; 3）&利用开放源结构化查询语言数据库引擎进一步开发反演偏移工具包SeisFlows SQLight和现有的工作流程管理工具，如Pegasus;以及4）在最短的9秒内使用数千次地震的数据库执行全球伴随地震层析成像。任务4包含了提案的主要目标，但如果不同时处理其他任务，就无法完成任务4。

项目成果

Seismic waveform inversion best practices: regional, global and exploration test cases

地震波形反演最佳实践：区域、全球和勘探测试案例

• DOI: 10.1093/gji/ggw202
• 发表时间: 2016
• 期刊: Geophysical Journal International
• 影响因子: 2.8
• 作者: Modrak, Ryan;Tromp, Jeroen
• 通讯作者: Tromp, Jeroen

Impact of topography and three-dimensional heterogeneity on coseismic deformation

• DOI: 10.1093/gji/ggz060
• 发表时间: 2019-05-01
• 期刊: GEOPHYSICAL JOURNAL INTERNATIONAL
• 影响因子: 2.8
• 作者: Langer, Leah;Gharti, Hom Nath;Tromp, Jeroen
• 通讯作者: Tromp, Jeroen

Global adjoint tomography: first-generation model

• DOI: 10.1093/gji/ggw356
• 发表时间: 2016-12-01
• 期刊: GEOPHYSICAL JOURNAL INTERNATIONAL
• 影响因子: 2.8
• 作者: Bozdag, Ebru;Peter, Daniel;Pugmire, David
• 通讯作者: Pugmire, David

Radial anisotropy of the North American upper mantle based on adjoint tomography with USArray

• DOI: 10.1093/gji/ggx305
• 发表时间: 2017-10
• 期刊: Geophysical Journal International
• 影响因子: 2.8
• 作者: Hejun Zhu;D. Komatitsch;J. Tromp

Spectral-infinite-element simulations of coseismic and post-earthquake deformation

同震和震后变形的谱无限元模拟

• DOI: 10.1093/gji/ggy495
• 发表时间: 2018
• 期刊: Geophysical Journal International
• 影响因子: 2.8
• 作者: Gharti, Hom Nath;Langer, Leah;Tromp, Jeroen
• 通讯作者: Tromp, Jeroen