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。基拉韦厄火山是研究玄武岩岩浆过程的首选地点。它是世界上监测最好、最活跃的火山之一。野外、岩石学、地球化学和地球物理研究已经圈定了其从地幔源到地表的基本岩浆管道系统。现代和古代基拉韦厄火山熔岩为破译夏威夷地幔柱内部成分异质性的本质以及评估岩浆的产生、运输和储存过程提供了重要线索。以前对历史和史前基拉韦厄山顶熔岩的研究记录了几十年到几百年的周期地球化学变化。从历史上看，这些成分的变化与一些因素相关，如喷发率（枯竭的火山源似乎经历了较低程度的融化，产生的岩浆较少）和罕见的爆炸性喷发（如1924年）。正在进行的28年，体积（3 km3） Pu？你啊?o火山喷发揭示了熔岩化学的短期趋势（年），这种趋势可能是由夏威夷羽流（包括最近枯竭的莫纳罗亚源）中小规模成分不均匀性的融化所控制的。目前，基拉韦厄火山有两次活跃喷发：O（1983-至今）对其东部裂谷带的影响以及火山的一次新喷发？哈勒玛？乌玛？u(2008年至今)。本文拟从岩石学、矿物化学、全岩主微量元素丰度、Pb、Sr、Nd和O同位素比值三方面探讨基拉韦厄熔岩过去、现在和未来的组成变化。现在和未来的变化：将涉及两个时间序列实验，使用来自当前普乌奥？哈勒玛？乌玛？u喷发。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（例如，晶体分馏和/或岩浆混合）之后，这些数据将允许对地幔过程进行评估。第二，来自Halema?uma？峰顶喷发将与同时期的普洱茶进行比较。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火山的结构。S岩浆管道系统。在两个遥远的喷口位置（山顶和裂谷带）持续的喷发为追踪岩浆在火山中的运动提供了机会。作为时间和空间的函数的管道系统使用熔岩化学。这项工作将对其他玄武岩火山产生影响。第三，基拉韦厄火山的最后200多公里？研究人员将利用从1.7公里和2.0公里长、连续取芯的科学观测孔（SOH）钻孔中获得的熔岩来评估其演化。（SOH）岩心代表了夏威夷火山早期屏蔽阶段的研究很少，夏威夷科学钻探项目（HSDP）在莫纳克亚火山没有对其进行采样。为了更好地约束SOH岩心样品的年龄，提出对14个样品进行高精度的40Ar-39Ar年龄测定。研究结果将用于基拉韦厄火山？S火山生长速率与地球化学演化。将比较同时期基拉韦厄火山（SOH，盾构期早期）和莫纳克亚火山（HSDP，盾构期晚期）熔岩的化学成分，以评估同时从夏威夷地幔柱东部克亚火山一侧提取的熔岩的地幔源和熔融条件。更广泛的影响。拟开展的研究包括：(1)利用基拉韦厄火山的研究成果，开发本科和研究生课程的教学模块，突出活火山的岩浆过程，强调合作学习和高级思维技能的发展；(2)指导一名博士后研究员、研究生和本科生；(3)向学校团体和当地社区就基拉韦厄火山喷发进行公开讲座。(4)更好地了解可能对生活质量产生不利影响的火山；(5)通过协作和利用设施加强国际和国家科学合作。

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.