"CSEDI: From fine to global scales: Integrated studies of the structure, dynamics, and mineral physics of the lower mantle"

“CSEDI：从精细到全球尺度：下地幔结构、动力学和矿物物理的综合研究”

• 批准号: 0855815
• 负责人: Michael Gurnis
• 金额: $ 35万
• 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: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0855815&HistoricalAwards=false
• 关键词: CSEDI; fine; global; scales; Integrated

The solid earth, the earth excluding the oceans and atmosphere, is a giant heat engine responsible for not only continental drift and plate tectonics, but also geological hazards (especially those from giant earthquakes) and for the formation of mineral and hydrocarbon resources. The purpose of this research is to better understand how this heat engine works by focusing on the earth's lower mantle. The lower mantle is the largest region of the planet by volume and the heat sources and physical processes there play a critical role in determining how the heat engine works. In this project, we will take a cooperative approach in which we will understand the basic material properties of earth materials under extreme pressures and temperatures; incorporate those experimental results into three-dimensional simulations of the earth's interior; and then test the predictions of both approaches with detailed studies of seismic waves passing through the earth's deep interior. We believe that there are three areas in which our work will have broad impact. First, our specialized work on the lower mantle is of broad interest to the scientific community because it improves our understanding of how the earth works as an interconnected, dynamic system. Second, we will partially support and mentor three Caltech graduate students in the Seismology Lab. and thereby contribute to the training of the next generation of scientists in the U.S. Third, our multidisciplinary approach will allow our students to become leaders in the internationally competitive field of global geophysics.Seismologists have revealed that the mantle side of the core mantle boundary (D") is extraordinarily complex with a myriad of fine structure (e.g. ~10 km to a few 100 km's). Thermal and chemical heterogeneity, solid-solid phase transitions, and melting within the lower mantle are probably all required in order to explain observed structure and suggest that the lower boundary of the mantle is as complex as the continental crust. Understanding the origin of the fine scale structure of the lower mantle, in general, and D", in particular, is key toward understanding how the solid Earth works as a globally interconnected system. In order to better understand this region from the different means available, this work will involve collaboration between a seismologist, a geodynamist, and an experimental mineral physicist.

固体地球，即不包括海洋和大气的地球，是一个巨大的热机，不仅负责大陆漂移和板块构造，而且还负责地质灾害(特别是来自大地震的灾害)和矿物和碳氢化合物资源的形成。这项研究的目的是通过关注地球下地幔来更好地了解这个热机是如何工作的。下地幔是地球上体积最大的区域，那里的热源和物理过程在决定热机如何工作方面发挥着关键作用。在这个项目中，我们将采取一种合作的方法，在这种方法中，我们将了解地球材料在极端压力和温度下的基本材料特性；将这些实验结果纳入地球内部的三维模拟；然后通过详细研究穿过地球深处的地震波来测试这两种方法的预测。我们认为，我们的工作将在三个领域产生广泛影响。首先，我们关于下地幔的专门工作引起了科学界的广泛兴趣，因为它提高了我们对地球是如何作为一个相互关联的动态系统工作的理解。其次，我们将部分支持和指导加州理工大学地震学实验室的三名研究生。第三，我们的多学科方法将使我们的学生成为具有国际竞争力的全球地球物理学领域的领导者。地震学家发现，核心地幔边界(D“)的地幔一侧异常复杂，具有无数的精细结构(例如约10公里到几个100公里)。为了解释观察到的结构，并暗示地幔的下界与大陆地壳一样复杂，可能需要进行热和化学不均匀、固体-固体相变以及下地幔内的熔融。了解下地幔细小尺度结构的起源，尤其是D“，是理解固体地球作为一个全球相互关联的系统工作的关键。为了从现有的不同手段更好地了解这一地区，这项工作将涉及地震学家、地球动力学家和实验矿物物理学家之间的合作。