Forward and Inverse Models of Coupled Plate Tectonics and Mantle Convection using Data Assimilation

使用数据同化的耦合板块构造和地幔对流的正演和反演模型

• 批准号: 0810303
• 负责人: Michael Gurnis
• 金额: $ 37.5万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0810303&HistoricalAwards=false
• 关键词: Forward; Inverse; Models; Coupled; Plate

In this project, we will study the forces that drive plate tectonics and continental drift. Plate tectonics is the surface expression of thermal convection, representing the overall process by which the earth acts as a giant heat engine. A basic understanding of mantle convection contributes to understanding processes that control natural hazards (great earthquakes) and the occurrence of oil (within deep, offshore sedimentary basins). In this project, we will develop sophisticated computer models that resolve the forces driving and resisting plate tectonic motions. The models will assimilate some data sets (meaning that they will be input as constraints) and then they will be tested by independent data. On a global scale, the models will be the most sophisticated (in terms of both resolution and physics) attempted by any group internationally. To achieve the resolution required, we may use the largest computers that NSF is now installing. An important impact of the project will be the training of two Ph.D. students in geophysics. They will gain enormous experience with sophisticated numerical methods, supercomputing technologies, and the linkage of data with numerical models, especially the linkage between earth dynamics and sedimentary basin evolution. These skill sets are important for scientists needed by international oil companies in their search for oil in deep sedimentary basins.In our research, we link plate motions, mantle structure, and vertical motions with forward and inverse numerical models. The research will require a greater level of data integration than can now be achieved with a combination of software we have developed. This research involves three closely applied topics. First, it involves the prediction of global plate motions as a function of time, using highly resolved finite element models in which the variable viscosity of the plate margins, slabs, and mantle wedges are accounted for. Second, it involves the prediction of global (eustatic) and relative sea level changes using a new paleogeography-mantle convection system that we have developed. Third, it involves further development and application of inverse and adjoint models using seismic tomography, dynamic topography constraints, and plate motions.

在这个项目中，我们将研究驱动板块构造和大陆漂移的力量。板块构造是热对流的表面表现，代表了地球作为一个巨大热机的整个过程。对地幔对流的基本了解有助于了解控制自然灾害（大地震）和石油出现（在深海、近海沉积盆地内）的过程。在这个项目中，我们将开发复杂的计算机模型来解析驱动和抵抗板块构造运动的力。模型将同化一些数据集（意味着它们将作为约束输入），然后通过独立数据进行测试。在全球范围内，这些模型将是国际上任何团体尝试过的最复杂的模型（在分辨率和物理方面）。为了达到所需的分辨率，我们可能会使用 NSF 目前安装的最大的计算机。该项目的一个重要影响将是培养两名博士。地球物理学专业的学生。他们将在复杂的数值方法、超级计算技术以及数据与数值模型的联系，特别是地球动力学与沉积盆地演化之间的联系方面获得丰富的经验。这些技能对于国际石油公司在深层沉积盆地寻找石油所需的科学家来说非常重要。在我们的研究中，我们将板块运动、地幔结构和垂直运动与正向和逆向数值模型联系起来。该研究需要比现在通过我们开发的软件组合实现更高水平的数据集成。这项研究涉及三个密切应用的主题。首先，它涉及使用高分辨率有限元模型来预测全球板块运动随时间的变化，其中考虑了板块边缘、板片和地幔楔的可变粘度。 其次，它涉及使用我们开发的新的古地理-地幔对流系统来预测全球（海平面）和相对海平面变化。第三，它涉及使用地震层析成像、动态地形约束和板块运动的逆模型和伴随模型的进一步开发和应用。