Secondary Hawaiian Hotspot Volcanism: What, When, Where, and Why?

夏威夷次生热点火山活动：什么、何时、何地以及为什么？

• 批准号: 0510482
• 负责人: Michael Garcia
• 金额: --
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-10-01 至 2011-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0510482&HistoricalAwards=false
• 关键词: Secondary; Hawaiian; Hotspot; Volcanism; What; Secondary; Hawaiian; Hotspot; Volcanism; What

Many oceanic volcano chains are formed by hotspots in the Earth's mantle. Most of the volcanism associated with hotspots is thought to occur directly over the mantle hotspot constructing features Hawaiian, Canary, Society island chains. However, this main phase is commonly followed by a period of quiescence and then a secondary volcanic phase. Diamond Head volcano on O`ahu, Hawaii, is a textbook example of secondary volcanism. The cause of such late-stage volcanism remains an enigma. This three-year project, funded jointly by the Divisions of Earth and Ocean Sciences, will examine the what (compositions), where (distribution and volumes), when (ages), and why (mechanisms) of secondary volcanism on and around the northern Hawaiian Islands. It is a coordinated land- and sea-based project with four main phases: (1) onshore mapping, sampling, and compilation of water well information to determine the volumes, ages and compositions of rejuvenated volcanism on Kaua`i and O`ahu. (2) A 28-day marine expedition to map the Kaua`i and Ni`ihau submarine volcanic fields with multibeam bathymetry and acoustic imagery, and to sample many of its volcanoes using the JASON2 ROV to characterize the petrology, geochemistry (major & trace elements, and isotopes) and ages of these lavas. (3) Integration of these results with previous surveys and petrologic/geochemical studies to establish a quantitative database for Hawaiian volcanic evolution. (4) Geodynamic modeling of this database to evaluate mechanisms for secondary volcanism. A first-order objective will be to establish how the submarine form of volcanism relates in space, time, volume, and composition to the nearby main shield volcanoes and their associated onshore secondary volcanism. Results will feed numerical modeling efforts to test proposed origins of secondary volcanism such as small-scale mantle convection driven by thermal and/or compositional buoyancy. The broader impacts of the proposed project include a K-12 interactive education program involving lesson-planning and interactive web activities with sciences classes throughout the state of Hawaii before, during and after our marine work. Also, we will mentor several graduate and undergraduate students on research projects. We will recruit underrepresented students in our research, give public lectures to school groups and the local community on Hawaiian volcanism, and gain a better understanding of the volcanic environment which impacts all life in Hawaii.

许多海洋火山连锁店是由地球地幔中的热点形成的。 人们认为，与热点相关的大多数火山主义都直接出现在建造夏威夷，金丝雀，社会岛链的地幔热点上。但是，该主要相通常是静止期，然后是二次火山相。 夏威夷O'Ahu的Diamond Head火山是二级火山主义的教科书示例。 这种晚期火山主义的原因仍然是一个谜。 这个为期三年的项目由地球和海洋科学的划分共同资助，将研究什么（成分），（分布和数量），当（年龄）以及为什么在夏威夷岛北部及其周围的中期火山主义（机制）。 这是一个协调的土地和海洋项目，具有四个主要阶段：（1）陆上映射，采样和水井信息的汇编，以确定Kaua`I和O'Ahu上恢复活力的火山的体积，年龄和组成。 （2）一项为期28天的海军陆战队探险，用于绘制带有多层测深和声学图像的Kaua`I和Ni`ihau潜艇火山田，并使用Jason2 Rov对其许多火山进行品尝，以表征岩石学，地球化学，地球元素和痕量元素以及这些型号的lavas和这些lavas。 （3）将这些结果与以前的调查和岩石学/地球化学研究相结合，以建立用于夏威夷火山进化的定量数据库。 （4）该数据库的地球动力学建模，以评估二级火山主义的机制。 一阶目标是建立火山的海底形式如何与附近的主盾牌火山及其相关的陆上二次火山之间的空间，时间，体积和成分之间的关​​系。结果将为数值建模工作提供测试，以测试二次火山主义的拟议起源，例如由热和/或组成浮力驱动的小规模对流。 拟议项目的更广泛的影响包括一项K-12互动教育计划，涉及在我们的海洋工作之前，之中和之后，涉及整个夏威夷的科学课程课程和互动网络活动。此外，我们将指导几位研究生和本科生的研究项目。我们将在研究中招募代表性不足的学生，向学校团体和当地社区提供有关夏威夷火山主义的公开演讲，并更好地了解影响夏威夷所有生活的火山环境。