Collaborative Research: Magmatic Evolution of Kilauea Volcano, Hawaii: Past, Present and Future

合作研究：夏威夷基拉韦厄火山的岩浆演化：过去、现在和未来

• 批准号: 1118741
• 负责人: Michael Garcia
• 金额: $ 26.74万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1118741&HistoricalAwards=false
• 关键词: Collaborative; Research; Magmatic; Evolution; Kilauea

Collaborative Research: Magmatic Evolution of Kilauea Volcano, Hawaii: Past, Present and FutureIntellectual Merit. Kilauea volcano is the premier location to study basaltic magmatic processes. It is one of the best monitored and most active volcanoes in the world. Field, petrologic, geochemical, and geophysical studies have delineated its basic magmatic plumbing system from the mantle source to the surface. Modern and ancient Kilauea lavas provide essential clues for deciphering the nature of compositional heterogeneity within the Hawaiian mantle plume and for assessing processes of magma generation, transport and storage. Previous studies of historical and prehistoric Kilauea summit lavas documented cyclic geochemical variations on a time scale of decades to centuries. Historically, these compositional variations correlate with factors such as eruption rate (more depleted sources appear to have undergone lower degrees of melting and produced less magma) and rare, explosive eruptions (e.g., 1924). Detailed investigation of the ongoing, 28-year-old, voluminous (3 km3) Pu?u O?o eruption has revealed shorter-term trends in lava chemistry (years) that may be controlled by the melting of small-scale compositional heterogeneities within the Hawaiian plume, including recently depleted and Mauna Loa-like sources. Currently, Kilauea has two active eruptions: Pu`u O?o (1983-present) on its east rift zone and a new eruption at the volcano?s summit, Halema?uma?u (2008-present).A three-part study is proposed involving petrography, mineral chemistry, whole-rock major and trace element abundances, and Pb, Sr, Nd and O isotope ratios to investigate past, present and future compositional variations in Kilauea lavas. Present and future variations: will involve two time series experiments using lavas from the current Pu`u O?o and Halema?uma?u eruptions. First, time-series petrologic and geochemical monitoring will document changes in eruptive behavior and/or lava chemistry. After assessing the effects of crustal processes (e.g., crystal fractionation and/or magma mixing), these data will allow evaluation of mantle processes. Second, the chemistry of juvenile glassy tephra from the Halema?uma?u summit eruption will be compared with contemporaneous Pu`u O?o rift zone lavas, and geophysical and other data collected by the USGS Hawaiian Volcano Observatory, to better delineate the architecture of Kilauea?s magmatic plumbing system. Sustained eruptions at two distant vent locations (summit and rift zone) provide opportunity to track the movement of magma through the volcano?s plumbing system as a function of time and space using lava chemistry. This work will have implications for other basaltic volcanoes. Third, the last 200+ ka of Kilauea?s evolution will be assessed using lavas from the ~1.7- and 2.0-km long, continuously cored Scientific Observation Hole (SOH) drill holes. The (SOH) core represents the poorly studied early shield stage of a Hawaiian volcano, which was not sampled by the Hawaii Scientific Drilling Project (HSDP) at Mauna Kea volcano. To better constrain ages for SOH core samples it is proposed to obtain high precision 40Ar-39Ar ages for 14 samples. The results will be used to model Kilauea?s volcanic growth rate and temporal geochemical evolution. The chemistry of coeval Kilauea (SOH, early shield stage) and Mauna Kea (HSDP, late shield stage) lavas will be compared to evaluate mantle source and melting conditions for lavas extracted contemporaneously from the eastern, Kea side of the Hawaiian plume.Broader Impacts. The proposed research will involve (1) developing teaching modules for undergraduate and graduate courses using the results from our Kilauea research to highlight magmatic processes at an active volcano and emphasize cooperative learning and development of higher order thinking skills, (2) mentoring a post-doctoral researcher, and graduate and undergraduate students, (3) giving public lectures to school groups and the local community on the eruptions of Kilauea, (4) gaining a better understanding of volcanoes, which can adversely influence the quality of life, and (5) increasing international and national scientific cooperation through collaboration and utilization of facilities.

合作研究：夏威夷基拉韦厄火山的岩浆演化：过去、现在和未来。 基拉韦厄火山是研究玄武岩浆过程的主要场所。它是世界上监测最好、最活跃的火山之一。野外地质、岩石学、地球化学和地球物理研究已经描绘出从地幔源区到地表的基本岩浆管道系统。现代和古老的基拉韦厄熔岩提供了重要的线索，破译夏威夷地幔柱内的成分不均匀性的性质，并评估岩浆生成，运输和存储的过程。以前对历史和史前基拉韦厄火山顶熔岩的研究记录了数十年至数百年时间尺度上的周期性地球化学变化。 从历史上看，这些成分变化与诸如喷发率（更多的贫化源似乎经历了较低程度的熔融，产生较少的岩浆）和罕见的爆炸性喷发（例如，1924年）。正在进行的详细调查，28岁，大量（3立方公里）浦？你好吗？火山爆发揭示了熔岩化学（年）的短期趋势，这可能是由夏威夷羽流内的小规模成分不均匀性，包括最近耗尽和莫纳罗亚山一样的来源融化控制。目前，基拉韦厄有两个活跃的喷发：普乌奥？o（1983年至今）在其东部裂谷带和一个新的火山喷发？哈勒玛，我们要去峰会吗？uma？建议进行一项三部分研究，涉及岩相学、矿物化学、全岩主要和微量元素丰度以及Pb、Sr、Nd和O同位素比率，以调查基拉韦厄熔岩过去、现在和未来的成分变化。现在和未来的变化：将涉及两个时间序列实验使用熔岩从目前的Pu`u O？O和Halema？uma？u爆发。首先，时间序列岩石学和地球化学监测将记录喷发行为和/或熔岩化学的变化。在评估了地壳过程的影响之后（例如，晶体分离和/或岩浆混合），这些数据将允许地幔过程的评估。第二，来自Halema的幼年玻璃质火山灰的化学性质？uma？u山顶喷发将与同时代的Pu`u O？o裂谷带熔岩，以及美国地质勘探局夏威夷火山观测站收集的地球物理和其他数据，以更好地描绘基拉韦厄的结构？的岩浆管道系统。持续喷发在两个遥远的喷口位置（首脑会议和裂谷区）提供了机会，以跟踪岩浆运动通过火山？的管道系统作为一个功能的时间和空间使用熔岩化学。这项工作将对其他玄武岩火山产生影响。 第三，基拉韦厄最后200+ ka？将使用从~1.7-和2.0-km长的连续取芯的科学观测孔（SOH）钻孔中获得的熔岩来评估火山的演化。（SOH）岩心代表了夏威夷火山的早期盾状阶段，该阶段研究不足，夏威夷科学钻探项目（HSDP）未在莫纳克亚火山取样。为了更好地约束SOH岩心样品的年龄，建议获得14个样品的高精度40 Ar-39 Ar年龄。结果将被用来模拟基拉韦厄？的火山生长速率和时间地球化学演化。将比较同时代的基拉韦厄火山（SOH，早期盾阶段）和莫纳克亚火山（HSDP，晚期盾阶段）熔岩的化学性质，以评估从夏威夷羽流的东部凯阿一侧同时提取的熔岩的地幔来源和熔融条件。拟议的研究将涉及（1）利用我们的基拉韦厄研究成果为本科生和研究生课程开发教学模块，以突出活火山的岩浆过程，并强调合作学习和高阶思维技能的发展，（2）指导博士后研究员，研究生和本科生，（3）为学校团体和当地社区举办关于基拉韦厄火山爆发的公开讲座，（4）更好地了解火山，因为火山会对生活质量产生不利影响，（5）通过合作和利用设施，加强国际和国内的科学合作。