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: 1161046
• 负责人: Michael Gurnis
• 金额: $ 36万
• 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: 2012
• 资助国家: 美国
• 起止时间: 2012-05-15 至 2015-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1161046&HistoricalAwards=false
• 关键词: CSEDI; fine; global; scales; Integrated

Located nearly 2,000 miles below the surface of the Earth, the core mantle boundary (CMB) represents one of the most dramatic layers within our planet (second only to Earth's surface). Changes across the layer exert a primary influence on the cooling of the Earth, the dynamics of the core (and hence Earth's protective magnetic field), and on the dynamics of the mantle (expressed as plume-related volcanism at the Earth's surface). We aim to answer the question, how do physical and chemical processes in the core-mantle boundary region modulate the planet's mass and heat flux, and what are the consequences for the whole Earth system? This layer is not just physically remote, but the conditions there are extremely challenging to reproduce experimentally: pressures over one million times atmospheric and temperatures approaching 6000 degrees Fahrenheit. Although, enormous strides have been made in recent decades towards understanding the dynamics of the deep Earth system using techniques from different disciplines (e.g., geodynamics, seismology, mineral physics), no single method provides a unique answer. Consequently, the project will combine data, methods, and expertise to attempt to overcome this non-uniqueness. The project will support (at least partially) three graduate students working in our multi-disciplinary environment; the students involved with this work will individually become exposed to state-of-the-art skills that can be applied within the Earth sciences and more broadly in science and engineering. Major advances in experimental and computational facilities, instrument resolution, and deployment of the USArray are providing unprecedented opportunities to understand the processes operating in the deep Earth. However, we lack a comprehensive knowledge of how the deepest parts of the Earth operate within the global Earth system. The project will encompass comprehensive laboratory measurements, ab-initio calculations, seismic observations, and 4-D models. We will develop an integrated multi-scale understanding of the chemical and physical processes at the boundary between solid mantle and fluid core which couple across spatial and temporal scales, while improving data resolution and modeling capabilities to better predict the evolution of the earth system. We will apply seismic modeling techniques to better constrain the structure of the mantle and we will mine and model seismic waveform data from regional arrays (US, Chinese and Japanese seismic networks). A host of forward 2-D and spherical dynamic models linked to a new paleogeographic system will be used to predict and interpret seismic data. We will perform laboratory experiments under high-PT and determine elastic properties and equations of state of candidate phases. The geodynamic and seismic models will use the best constraints from mineral physics, including our experimental work.

地核地幔边界（CMB）位于地球表面以下近2000英里处，是地球上最具戏剧性的层之一（仅次于地球表面）。这一层的变化对地球的冷却、地核的动力学（以及地球的保护性磁场）和地幔的动力学（表现为地球表面与羽流有关的火山活动）产生了主要影响。我们的目标是回答这样一个问题，即地核-地幔边界区域的物理和化学过程如何调节地球的质量和热通量，以及对整个地球系统的影响是什么？这一层不仅在物理上遥远，而且那里的条件对实验重现也极具挑战性：压力超过大气的100万倍，温度接近6000华氏度。尽管近几十年来，利用不同学科（如地球动力学、地震学、矿物物理学）的技术，在了解地球深部系统的动力学方面取得了巨大进展，但没有一种方法能提供唯一的答案。因此，该项目将结合数据、方法和专业知识，试图克服这种非独特性。该项目将支持（至少部分）三名研究生在我们的多学科环境中工作；参与这项工作的学生将分别接触到最先进的技能，这些技能可以应用于地球科学，更广泛地应用于科学和工程。在实验和计算设施、仪器分辨率和USArray部署方面的重大进展，为了解地球深处的运行过程提供了前所未有的机会。然而，我们对地球最深处如何在全球地球系统中运作缺乏全面的了解。该项目将包括综合实验室测量、从头计算、地震观测和4-D模型。我们将开发一个综合的多尺度的理解在固体地幔和流体核之间的边界化学和物理过程的耦合跨越空间和时间尺度，同时提高数据分辨率和建模能力，以更好地预测地球系统的演化。我们将应用地震建模技术来更好地约束地幔的结构，我们将从区域阵列（美国、中国和日本地震台网）中挖掘和模拟地震波形数据。与新的古地理系统相联系的一系列正演二维和球形动力学模型将用于预测和解释地震数据。我们将在高pt下进行实验室实验，并确定候选相的弹性特性和状态方程。地球动力学和地震模型将使用矿物物理学的最佳约束，包括我们的实验工作。