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

GSTDTAP

项目编号	1753354
	CAREER: Moving into the 3rd Dimension: Quantifying the influence of Magmatism, Tectonics, Hydrothermal Cooling, and Hotspots on the Dynamic Evolution of Divergent Plate Boundaries
	Eric Mittelstaedt
主持机构	University of Idaho
项目开始年	2018
	2018-05-01
项目结束日期	2023-04-30
资助机构	US-NSF
项目类别	Continuing grant
项目经费	87601(USD)
国家	美国
语种	英语
英文摘要	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.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/72535
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Eric Mittelstaedt.CAREER: Moving into the 3rd Dimension: Quantifying the influence of Magmatism, Tectonics, Hydrothermal Cooling, and Hotspots on the Dynamic Evolution of Divergent Plate Boundaries.2018.