CAREER: Moving into the 3rd Dimension: Quantifying the influence of Magmatism, Tectonics, Hydrothermal Cooling, and Hotspots on the Dynamic Evolution of Divergent Plate Boundaries

职业：进入第三维度：量化岩浆作用、构造、热液冷却和热点对发散板块边界动态演化的影响

• 批准号: 1753354
• 负责人: Eric Mittelstaedt
• 金额: $ 59.96万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1753354&HistoricalAwards=false
• 关键词: CAREER; Moving; into; 3rd; Dimension

The theory of plate tectonics states that the surface of the Earth is made up of numerous moving plates. The interior regions of these plates are believed to be rigid and strong, while boundaries in the ocean where the plates spread apart, mid-ocean ridges, are thin, hot, and weak. In contrast to the standard expectations of plate tectonic theory, observations find that sections of mid-ocean ridges often shift, or jump, from weak boundaries to strong plate interiors. As a result, jumps of mid-ocean ridges can change the size and shape of the tectonic plates and even create micro-continents (small slivers of continental material) when they jump into continental regions. Mid-ocean ridge jumps are believed to result after some process weakens a nearby plate interior. However, scientists do not know the reasons or driving forces behind this weakening. Previous studies examined mid-ocean ridge jumps in a 2D geometry, but could not address several key processes that would control their formation, leaving a gap in our understanding of plate tectonics. In this study, innovative laboratory and state-of-the-art 3D numerical simulations will be used to isolate the processes that lead to mid-ocean ridge jumps. Understanding these processes will improve understanding of the thermal evolution of the planet and the locations of potential mineral resources associated with past hydrothermal activity. The educational component of this CAREER award has two primary goals: 1) to motivate young students (~10-18 years old) to pursue STEM-based inquiry through interactive, marine geology-based video games that are engaging, entertaining, and provide easily accessible opportunities for in-depth exploration of marine geology topics, and 2) to involve several interdisciplinary groups of undergraduate students in a hands-on, engaging experience where they learn STEM skills and explore marine geologic data.Observations of numerous relic spreading centers and micro-continents formed by sudden relocations or jumps of ridge axes indicate that mid-ocean ridge jumps regularly shift to new, off-axis locations. This project's primary research goal is to quantify the processes that govern ridge jumps and thereby test the hypothesis that there are predictable length- and time-scales for ridge jump formation. This goal is split into three objectives that aim to quantify: 1) the role of magmatic accretion in propagation of nascent rifts adjacent to established ridges and consequent formation of transform faults or overlapping spreading centers; 2) mantle plume-induced ridge jumps in oceanic lithosphere; and 3) micro-continent formation by jumps into continental lithosphere. These objectives will be addressed with 3D numerical simulations and innovative laboratory experiments using colloidal fluids. To establish testable predictions from these models and experiments, results will be used to derive functional relationships between length- and time-scales of ridge jumps and observable quantities such as spreading rate, ridge migration rate, seafloor age, and melt flux. These relationships will be evaluated through comparison to a new database of jump statistics including jump distance, final segment length, transform fault or overlapping spreading center formation rate and location, and the time between repeat jumps.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

板块构造的理论指出，地球表面由许多移动的板组成。这些板的内部区域被认为是刚性和牢固的，而板散开的海洋边界则是薄的，薄的，热且弱的。与板块构造理论的标准期望相反，观察发现中端脊的部分通常会从弱边界转移或跳跃到强板内部。结果，中山山脊的跳跃可以改变构造板的大小和形状，甚至在跳入大陆区域时会产生微型容器（大陆材料的小片）。人们认为，在某些过程削弱了附近的板块内部后，会产生大范围的山脊跳跃。 但是，科学家不知道这种弱化背后的原因或驱动力。先前的研究检查了中海脊以2D几何形状跳跃，但无法解决几个可以控制其形成的关键过程，在我们对板块构造的理解中留下了差距。 在这项研究中，将使用创新的实验室和最先进的3D数值模拟来隔离导致中海脊跳跃的过程。了解这些过程将提高人们对行星的热演化以及与过去热液活动相关的潜在矿物资源的位置。 The educational component of this CAREER award has two primary goals: 1) to motivate young students (~10-18 years old) to pursue STEM-based inquiry through interactive, marine geology-based video games that are engaging, entertaining, and provide easily accessible opportunities for in-depth exploration of marine geology topics, and 2) to involve several interdisciplinary groups of undergraduate students in a hands-on, engaging experience where they learn STEM skills and explore marine geologic数据。由突然搬迁或山脊轴跳跃形成的众多遗物扩散中心和微型企业的观察表明，中海脊定期转移到新的非轴上位置。该项目的主要研究目标是量化脊跃跳的过程，从而检验以下假设：山脊跳跃形成有可预测的长度和时间尺度。该目标分为旨在量化的三个目标：1）岩浆积聚在与已建立山脊相邻的新生裂痕传播中的作用，以及随之而来的变换断层或重叠的扩散中心的形成； 2）柱羽诱导的山脊在海洋岩石圈中跳跃； 3）跳入大陆岩石圈的微型大陆形成。这些目标将通过3D数值模拟和使用胶体流体进行创新的实验室实验来解决。为了从这些模型和实验中建立可测试的预测，结果将用于得出山脊跳跃的长度和时间尺度之间的功能关系，以及可观察到的数量，例如扩散率，山脊迁移率，海底年龄和融化速度。这些关系将通过与跳跃统计的新数据库进行比较来评估，包括跳跃距离，最终部分长度，变换的故障或扩展中心的形成率和位置，以及重复跳跃之间的时间。这项奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估来通过评估来获得支持的。