CAREER: Phase Diagrams and Elasticity of Iron Alloys in the Earth's Core

职业：地核铁合金的相图和弹性

• 批准号: 1056670
• 负责人: Jung-Fu Lin
• 金额: $ 48.62万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-15 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1056670&HistoricalAwards=false
• 关键词: CAREER; Phase; Diagrams; Elasticity; Iron

Because of its remoteness, together with extremely high pressures and temperatures, most direct observations of the Earth's core properties have come from teleseismic studies, requiring large earthquake sources and well-positioned seismometers to detect weak wave signals that have traversed through the Earth's deepest interior. In the last two decades, deep-Earth scientists have unveiled a number of unusual and enigmatic phenomena of the core, including inner core anisotropy, differential rotation of the inner core, fine-scale seismic heterogeneity, and the possible existence of the prefer-orientated iron alloys in the inner core. Understanding these phenomena will help test hypotheses on the Earth's formation, elucidate the geochemistry and the history of the Earth's deep interior, and determine the dynamic behavior of Earth's solid inner core and liquid outer core. This CAREER award investigates the alloying effects of major candidate light elements on the phase diagram and elasticity of iron under relevant pressures and temperatures of the core in order to address pressing issues on its composition, thermal structures, and seismic features. Working together with theorists and experimentalists, results from this award will ultimately be used to construct a forward model for the expected velocities, composition, and temperature profiles in the core. The thermoelastic modeling aspects of the proposal will provide students and postdoctoral researchers with a great opportunity to collaborate with scientists in the fields of seismology and geodynamics, helping them understand how laboratory mineral physics data are applied to deep-Earth issues and what kinds of new data are most urgently needed by the community.The proposed mineral physics research uses synchrotron X-ray spectroscopies in a laser-heated diamond anvil cell designed to probe structural and elastic properties of iron alloys at pressure-temperature conditions of the Earth's core. Under the initiatives of the projects, students and postdoctoral researchers will have unique research opportunities to use advanced synchrotron X-ray facilities at the Advanced Photon Source to obtain laboratory results needed to decipher seismic and geochemical observations of the planet's core. This will contribute to the education of the next generation of independent researchers with a thorough knowledge of the Earth's deep interior. Outreach activities in this CAREER award focus on exposing K-12th graders to deep-Earth research by involving in the outreach summer programs. A collection of displayable materials with information about deep-Earth research will be made available to students and teachers in the Austin School Districts to support the dissemination of accurate scientific knowledge and enthusiasm. Results from this award will be disseminated broadly through teaching, seminars, conferences, and peer-reviewed publications.

由于其偏远，加上极高的压力和温度，对地球核心特性的大多数直接观察都来自远距离研究，需要大地震来源和位置良好的地震仪，以检测到地球上最深内部的弱波信号。在过去的二十年中，深地球科学家推出了许多核心的异常和神秘现象，包括内核各向异性，内核的差异旋转，细尺度的地震异质性以及优先面向的可能存在内核中的铁合金。了解这些现象将有助于检验地球形成的假设，阐明地球化学和地球深内部的历史，并确定地球固体内核和液体外核的动态行为。该职业奖研究了主要候选光元素对相关压力和核心温度下铁的相图和弹性的合金作用，以解决其组成，热结构和地震特征的压力问题。与理论家和实验者合作，该奖项的结果最终将用于构建核心中预期速度，成分和温度谱的前向模型。该提案的热弹性建模方面将为学生和博士后研究人员提供与地震学和地球动力学领域的科学家合作的绝佳机会，可帮助他们了解实验室矿物质物理学数据如何应用于深地球问题，以及哪些新数据类型社区最迫切需要。拟议的矿物质物理学研究在激光加热的钻石砧细胞中使用同步子X射线光谱，旨在探测地球核心压力温度条件下铁合金的结构和弹性特性。在项目的举措下，学生和博士后研究人员将有独特的研究机会，可以使用高级光子源的先进同步器X射线设施，以获取对地球核心的地震和地球化学观察所需的实验室结果。这将有助于对下一代独立研究人员的教育，并以深入了解地球深层内部。该职业生涯奖中的外展活动着重于通过参与外展夏季计划来使K-12年级的研究员接触深地球研究。一系列可展示的材料包含有关深地球研究的信息的集合，将为奥斯汀学区的学生和老师提供支持，以支持传播准确的科学知识和热情。该奖项的结果将通过教学，研讨会，会议和同行评审的出版物进行广泛传播。