Collaborative Research: Forward and inverse models of global plate motions and plate interactions

合作研究：全球板块运动和板块相互作用的正向和逆向模型

• 批准号: 1645775
• 负责人: Michael Gurnis
• 金额: $ 41万
• 依托单位: California Institute of Technology
• 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 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1645775&HistoricalAwards=false
• 关键词: Collaborative; Research; Forward; inverse; models

Part 1: This is a project in which geoscientists at Caltech and mathematicians at New York University will collaborate to better understand the forces responsible for the motion of continents and those responsible for great earthquakes. This is a mathematical and modeling project that will use existing observations to infer the forces which push and pull the tectonic plates around and the forces which cause the plates to slow down-essentially the resistance or friction inside the earth. The driving forces arise from the lower temperatures associated with the cold tectonic plates when they return to the inside of the earth. The resistance comes from several sources including the strength of the tectonic plates and the friction between the tectonic plates. Beyond those simple statements, scientists do not know precisely how those forces are balanced and this gap in their understanding means that society cannot precisely forecast where great earthquakes will occur. Great earthquakes, like the one that caused the Fukushima nuclear disaster in Japan in 2011, are the most destructive of all earthquakes. By harnessing new computational methods developed by the team and using supercomputers supported by NSF and the Department of the Energy, the collaborators will bring a new level of understanding to this problem. Essentially, the team will develop what are called inverse models in which they will go from the data (like the motion of the tectonic plates) to maps showing the relative strength of different tectonic boundaries. Inverse models are powerful methods, especially in the area of big data, but they require considerable investment in new mathematical techniques, algorithms and computer software. Key for this project is that for the first time, the key aspects of the physics will be incorporated at high resolution. Besides the scientific output, a key outcome of this project will be the training of graduate students and postdoctoral scholars. They will gain enormous experience with sophisticated numerical methods, inversion & optimization methods, supercomputing technologies, and the linkage of data with numerical models. The graduate students in the respective fields of geophysics and applied mathematics are highly sought after by the research community (academia and government research laboratories) and private industry (including the hydrocarbon industry). A key outcome will also be sophisticated new computer software that will efficiently utilize the largest supercomputers supported by the government and industry and this software will be donated to the NSF-supported software center for geophysics (the Computational Infrastructure for Geodynamics, CIG) for broader distribution throughout the scientific community.-Part 2: The team will use global forward and inverse models to determine the variations in mechanical coupling in subduction zones using present day plate motions and the along strike variation in the depth of oceanic trenches. Using plate motions, they will then apply the methods to the geological past and more fully establish the dynamic link between changing plate motions and how they translate into and result from changes in subduction including plate coupling, with specific linkages to geophysical and geological observations. The models will be high resolution (e.g. locally 1 km or less where needed) and fully incorporate the extreme variations and non-linearity in viscosity between the slab and mantle, hinge zone and interface between subducting and over-riding plates. They will use mathematically rigorous and computationally robust PDE-constrained optimization and uncertainty quantification approaches to infer mechanical parameters and coupling coefficients between plates. Global plate motions are primarily driven by the negative buoyancy within subducted slabs, but beyond that statement there is much less consensus on either the relative importance of other driving forces or the strength and nature of resisting forces. The failure to reach consensus on the complete force balance of plate tectonics and mantle flow manifests itself in fundamental unanswered questions, including the causes of changes in plate motions over millions of years, the variability in occurrence of great earthquakes at subduction zones, and the thermal and tectonic evolution of the earth, for example. These processes are likely related to how the forces within a subducting slab are transmitted and resisted through the bending (hinge) zone from the slab and into the subducting plate. In this project, the team will take a new generation of plate-mantle models in which the details of plate boundaries are resolved while cast as a mathematically rigorous and computationally robust parameter estimation problem linked to key observational data sets. They will achieve a much deeper understanding on the forces driving and resisting plate motions, the formal trade-off between parameters, the variation of plate coupling between subduction zones, and the evolution of the force balance on million-year time scales. The most important broader impact will be the training of several Ph.D. students in geophysics and applied mathematics and a postdoctoral scholar. The students and post-docs will gain enormous experience with sophisticated numerical methods, inversion & optimization methods, supercomputing technologies, and the linkage of data with numerical models. The project will allow a young investigator in applied mathematics to more closely collaborate with earth scientists on critical scientific interest. At the end of the project the team will release the adjoint Rhea-II code to the community. Scientific impacts will be with the GPlates-CitcomS-Rhea linkage. The team will reach a new level of integration between dynamic flow models, plate kinematics and seismic tomography, that could have broad application in the geosciences. Their work could impact several large programs. The geodynamic hypotheses could result in predictions that could be tested with deep sea drilling under the auspices of IODP ocean drilling. The inference of the mechanical coupling along strike in subduction zones will be of significant use to better evaluate the role of geodynamic factors influencing the occurrence of great earthquakes and indirectly assist in the evaluation of seismic hazards.

第1部分：这是一个项目，在该项目中，加州大学的地球科学家和纽约大学的数学家将合作，以更好地了解负责大陆运动的力量以及负责大地震的运动。这是一个数学和建模项目，它将使用现有的观测值来推断推动和拉动构造板的力，以及导致板的力，而板的力则缩减地球内部的电阻或摩擦力。驱动力是由与冷构造板相关的较低温度返回地球内部时引起的。电阻来自多个来源，包括构造板的强度和构造板之间的摩擦。除了这些简单的陈述外，科学家还不知道这些力量是如何平衡的，而这种差距意味着社会不能准确预测发生巨大地震的地方。大地震，就像2011年在日本造成福岛核灾难的地震一样，是所有地震中最具破坏性的地震。通过利用团队开发的新计算方法并使用NSF和能源部支持的超级计算机，合作者将为这个问题带来新的理解水平。从本质上讲，团队将开发所谓的逆模型，在这些模型中，它们将从数据（例如构造板的运动）转变为显示不同构造边界的相对强度的地图。逆模型是强大的方法，尤其是在大数据领域，但它们需要对新的数学技术，算法和计算机软件进行大量投资。该项目的关键是，第一次将以高分辨率纳入物理学的关键方面。 除了科学产出外，该项目的关键结果还将是研究生和博士后学者的培训。他们将通过复杂的数值方法，反转和优化方法，超级计算技术以及数据与数值模型的链接获得巨大的经验。 研究界（学术界和政府研究实验室）和私营企业（包括碳氢化合物行业），高地地球物理和应用数学领域的研究生受到了极大的追捧。一个关键的结果还将是复杂的新计算机软件，该软件将有效利用政府和行业支持的最大超级计算机，该软件将捐赠给NSF支持的地球物理学软件中心（地球都该地球都该地球都市的计算基础设施中心）（地球态组织的计算基础设施，将在整个科学社区中进行更广泛的cig）来确定全球型号：partiment in Global offortion in Angroment in Angroment in Angultion in drovions in Global offortion in Drivions in Drivation in Drivation in Drivation in Drivation in drivation inderfort in Driviation indrivation。区域使用当前的板块运动和海洋沟深度的沿撞击变化。然后，他们将使用板运动将方法应用于地质过去，并更充分地建立变化的板块运动之间的动态联系，以及它们如何转化为俯冲的变化，包括板耦合，以及与地球物理和地质观察的特定链接。这些模型将是高分辨率（例如，在需要的情况下局部1 km或更少），并完全融合了平板和地幔，铰链区，铰链区域以及俯冲和过度骑行板之间的粘度的极端变化和非线性。他们将使用数学上严格且计算强大的PDE受限优化和不确定性量化方法来推断板之间的机械参数和耦合系数。全球板的运动主要是由俯冲板内的负浮力驱动的，但是除了该陈述之外，就其他驱动力的相对重要性或抵抗力的强度和性质所达成的共识要少得多。未能就板块构造和地幔流的完全力平衡达成共识，这表现在基本的未解决问题中，包括板块运动变化数百万年以上的原因，例如，俯冲鞋底发生大地震的变化，以及地球的热和构造进化。这些过程可能与俯冲平板内的力如何通过弯曲（铰链）区域从板块转移到俯冲板中有关。在这个项目中，团队将采用新一代的板甲板模型，其中解决了板边界的细节，同时将其作为数学上严格且计算上可靠的参数估计问题与关键观察数据集有关。他们将对驾驶和抵抗板运动的力，参数之间的形式权衡，俯冲带之间的板耦合变化以及力平衡在百万年度时间尺度上的演变来深入了解。最重要的更广泛的影响是培训多个博士学位。地球物理学和应用数学和博士后学者的学生。学生和毕业后将通过复杂的数值方法，反转和优化方法，超级计算技术以及数据与数值模型的链接获得丰富的经验。 该项目将允许一名年轻的应用数学研究人员就批判性的科学兴趣与地球科学家进行更紧密的合作。在项目结束时，团队将向社区发布伴随的RHEA-II代码。科学的影响将带来Gplates-citcoms-rhea链接。 该团队将在动态流模型，板运动学和地震层析成像之间达到新的整合水平，这些模型可能在地球科学中具有广泛的应用。 他们的工作可能会影响几个大型计划。地球动力学假设可能会导致预测，可以通过在IODP海洋钻探的主持下进行深海钻孔进行测试。俯冲带中机械耦合的推断将有很大的用途，可以更好地评估影响大地震发生的地球动力因素的作用，并间接帮助评估地震危害。

项目成果

Subduction Duration and Slab Dip

• DOI: 10.1029/2019gc008862
• 发表时间: 2020-04-01
• 期刊: GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
• 影响因子: 3.5
• 作者: Hu, Jiashun;Gurnis, Michael
• 通讯作者: Gurnis, Michael

Reconstruction of the Cenozoic deformation of the Bohai Bay Basin, North China

• DOI: 10.1111/bre.12470
• 发表时间: 2020-05
• 期刊: Basin Research
• 影响因子: 3.2
• 作者: Yinbing Zhu;Shaofeng Liu;Bo Zhang-;M. Gurnis;P. Ma

East African topography and volcanism explained by a single, migrating plume

东非地形和火山活动由单一的迁移羽流解释

• DOI: 10.1016/j.gsf.2020.01.003
• 发表时间: 2020
• 期刊: Geoscience Frontiers
• 影响因子: 8.9
• 作者: Hassan, Rakib;Williams, Simon E.;Gurnis, Michael;Müller, Dietmar
• 通讯作者: Müller, Dietmar

Constraining absolute plate motions since the Triassic

自三叠纪以来限制绝对板块运动

• DOI: 10.1029/2019jb017442
• 发表时间: 2019
• 期刊: Journal of geophysical research
• 作者: Tetley, M.G.

Contrasted East Asia and South America tectonics driven by deep mantle flow

• DOI: 10.1016/j.epsl.2019.04.025
• 发表时间: 2019-07
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Ting Yang;Louis Moresi;M. Gurnis;Shaofeng Liu;D. Sandiford;S. Williams;F. Capitanio