Collaborative Research: Using the Rurutu hotspot to evaluate mantle motion and absolute plate motion models

合作研究：利用鲁鲁图热点评估地幔运动和绝对板块运动模型

• 批准号: 1358875
• 负责人: Matthew Jackson
• 金额: $ 18.43万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2015-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1358875&HistoricalAwards=false
• 关键词: Collaborative; Research; Using; Rurutu; hotspot

Linear tracks of submarine volcanoes (i.e., the Hawaiian-Emperor and Louisville volcanic chains) define the trace of the two longest-lived Pacific hotspots. These two hotspot tracks have long been used to model tectonic plate motion and define how the continents have moved over the face of the globe over time. It has generally been believed that hotspots, which originate deep in the mantle, are fixed and that, as the plate moves over it, the hot spot punches through the crust resulting in a linear chain of volcanoes that can be used to show the speed and direction of plate motion over 10's of millions of years. Mounting evidence now, however, indicates that hotspots may not actually be fixed with respect to the mantle or each other. To test the hypothesis of a moving hotspot reference frame, this research will define a third, long-lived, Pacific hotspot track, the Rurutu hotspot, and compare it with the Hawaiian-Emperor and Louisville chains. Twenty submarine volcanoes near the Samoa Islands in the western Pacific Ocean will be sampled and geochemical analyses of the lavas will be collected. Argon, produced from radioactive decay, will be used to determine the ages of the volcanoes. The chemisty of the lavas, especially the elemental abundances and the Sr, Ne, Pb, and Hf isotopes signatures, will be used to (1) distinguish Rurutu volcanoes from unrelated ones and (2) determine the geochemical fingerprint and evolution of the hotspot. Samples dredged from the seafloor will be described and analyzed on the ship by Laser Induced Breakdown Spectroscopy. Mapping and marine geophysical data will be collected and used to guide potential dredging targets. Broader impacts include a strong and large student training component in which three graduate students and 10 undergraduates will go to sea and be intimately involved in the project. This will help build a more diverse scientific workforce by recruiting students from a Hispanic Serving Institution in Texas and training them in state-of-the-art geochemical analysis and data interpretation. This research will foster inter-institutional collaboration between three institutions and will support two early career investigators.

海底火山的线性轨迹（即，夏威夷-帝王火山和路易斯维尔火山链）确定了两个寿命最长的太平洋热点的踪迹。 这两个热点轨迹长期以来一直被用来模拟构造板块运动，并定义大陆如何随着时间的推移在地球仪表面移动。 人们普遍认为，起源于地幔深处的热点是固定的，当板块在其上移动时，热点穿透地壳，导致线性火山链，可以用来显示数十亿年来板块运动的速度和方向。 然而，现在越来越多的证据表明，热点实际上可能并不是相对于地幔或彼此固定的。 为了验证移动热点参考系的假设，本研究将定义第三个长期存在的太平洋热点轨道，Rurutu热点，并将其与夏威夷皇帝和路易斯维尔链进行比较。 将对西太平洋萨摩亚群岛附近的20座海底火山进行取样，并收集熔岩的地球化学分析。由放射性衰变产生的氩气将用于确定火山的年龄。 熔岩的化学成分，特别是元素丰度和Sr、Ne、Pb和Hf同位素特征，将用于（1）区分Rurutu火山和不相关的火山，（2）确定热点的地球化学指纹和演化。 将在船上通过激光诱导击穿光谱法对从海底挖掘的样品进行描述和分析。 将收集绘图和海洋地球物理数据，并用于指导潜在的疏浚目标。更广泛的影响包括一个强大而庞大的学生培训部分，其中三名研究生和10名本科生将出海，并密切参与该项目。这将有助于通过从德克萨斯州的西班牙裔服务机构招募学生，并在最先进的地球化学分析和数据解释方面对他们进行培训，从而建立一支更加多样化的科学队伍。 这项研究将促进三个机构之间的机构间合作，并将支持两名早期职业调查员。