Modelling earthquakes and earth,s interior based upon exascale simulations of seismic wave propagation

基于亿亿级地震波传播模拟来模拟地震和地球内部

• 批准号: 402764-2010
• 负责人: Liu, Qinya
• 金额: $ 6.63万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: G8 Initiative Research Councils on Multilateral Research Funding
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=488169
• 关键词: Modelling; earthquakes; earth; interior; based

We propose to use modern numerical methods and computers to improve images of earthquakes and Earth's interior based upon forward and inverse simulations of seismic wave propagation. The simulations are based upon a spectral-element method and account for heterogeneity in the crust and mantle, topography, anisotropy, attenuation, fluid-solid interactions, self-gravitation, rotation, and the oceans. On future exascale machines we will able to reach frequencies well below 1 Hz in global simulations. Our objective is to go beyond classical traveltime tomography, and to use information contained in entire seismic waveforms. By drawing connections between seismic tomography, adjoint methods popular in climate and ocean dynamics, and time-reversal imaging, we have demonstrated that one iteration in tomographic inversions may be performed based upon just two numerical simulations for each earthquake: one calculation for the current model and a second adjoint calculation that uses time-reversed signals at the receivers as simultaneous, fictitious sources. This has finally opened the door to solving the 3D inverse problem, namely the problem of using the remaining differences between the data and the

我们建议利用现代数值方法和计算机在地震波传播的正演和反演模拟的基础上改进地震和地球内部的图像。模拟基于谱元方法，考虑了地壳和地幔的非均质性、地形、各向异性、衰减、流固相互作用、自引力、自转和海洋。在未来的百亿亿次机器上，我们将能够在全球模拟中达到远低于1hz的频率。我们的目标是超越经典的走时层析成像，并使用包含在整个地震波形中的信息。通过绘制地震层析成像、气候和海洋动力学中流行的伴随方法和时间反转成像之间的联系，我们已经证明，层析成像的一次迭代可以基于每次地震的两次数值模拟来执行：一次计算当前模型，第二次伴随计算使用接收器上的时间反转信号作为同时的虚拟源。这最终打开了解决三维逆问题的大门，即利用数据与数据之间的剩余差异的问题