Collaborative Research: What lies beneath: An investigation of subglacial silicic magma systems (Vatnajokull, Iceland)

合作研究：底层是什么：冰下硅质岩浆系统的调查（冰岛瓦特纳冰原）

• 批准号: 2219431
• 负责人: Tenley Banik
• 金额: $ 21.17万
• 依托单位: Board of Trustees of Illinois State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2219431&HistoricalAwards=false
• 关键词: Collaborative; Research; What; lies; beneath

Iceland is positioned where a mid-ocean ridge and a mantle plume intersect at high latitude, resulting in dynamic and dangerous volcano-ice interactions. Two of Iceland’s four most historically active volcanoes (Grímsvötn and Bárðarbunga) occur near the intersection of the ridge and plume, but they are largely obscured from view by Vatnajökull, an ice cap that covers ~10% of Iceland’s surface area. There are indications that glacial retreat can lead to increased eruption rates by destabilizing existing magma bodies and even prompting new magma generation. As climate continues to change and Iceland’s ice caps continue to thin, there is increasing concern about the impacts on subglacial volcanic systems and their associated hazards. It is important to better understand past and present behavior of subglacial volcanic systems to better prepare for future volcanic threats. The primary objective of this study is to explore the origin, evolution, age, and longevity of magmas under Vatnajökull in order to better understand Iceland’s glacio-volcanic hazard potential, while simultaneously learning about a geologically unique part of the world. This work will strengthen existing, and facilitate new, collaborations with domestic and international scientists in the field and in analytical labs. It will also create opportunity for community engagement and public education, and provide rigorous research experiences for 6+ undergraduate students, a majority of whom are from traditionally under-represented backgrounds.In Iceland, silicic material accounts for ~10% of the exposed crust; at central volcanoes, this amount increases to ~30%. Volcanic systems beneath Vatnajökull appear to have a paucity of silicic material relative to their subaerial counterparts. This may be a consequence of the proximity to the ridge-plume intersection, or (more likely) a consequence of poor exposure leading to sample bias. Since silicic magmas have the potential to erupt more explosively and with greater associated hazards than basaltic magmas, it is important to understand the role they may play at the productive, active, systems obscured from view by Vatnajökull. The research questions to be investigated are: To what extent are silicic materials associated with Bárðarbunga, Grímsvötn, and neighboring Kverkfjöll? Are collected silicic materials from active magmatic systems, older bedrock, or a combination? How do the geochemical characteristics of these systems’ silicic materials compare to those in the known rock record elsewhere in Iceland? What hazards do silicic magmas present in this dynamic rift-mantle plume-ice environment? Data generated in this study will facilitate mapping the regional distribution of subglacial silicic materials (both those associated with active volcanic systems and those from older bedrock). Evidence from nunatak and moraine rocks (major and trace elements; Hf, Nd, and Pb isotopes; petrography) and their accessory minerals (zircon: U-Th and U-Pb dates, O and Hf isotopes, trace elements; apatite: trace elements, volatiles) will make it possible to decipher the petrogenetic origins and evolution of silicic systems at Iceland’s most plume-affected, and most active, central volcanoes.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.

冰岛位于高纬度的海脊和地幔羽状的位置，导致动态和危险的火山冰相互作用。冰岛在山脊和羽流的交叉路口附近的冰岛四个最历史活跃的火山（GrímsVötn和Bárðarbunga）中，有两个发生在山脊和羽流附近，但它们在很大程度上被Vatnajökull从视线中遮住了，这是一个覆盖冰岛表面积约10％的冰盖。有迹象表明，冰川静修会通过破坏现有的岩浆物体甚至引发新的岩浆产生而导致喷发率提高。随着气候的不断变化，冰岛的冰盖继续变薄，人们对对冰山下火山系统及其相关危害的影响越来越担心。重要的是要更好地理解冰山下火山系统的过去和现在行为，以更好地为未来的火山威胁做准备。这项研究的主要目的是探索Vatnajökull下岩浆的起源，进化，年龄和寿命，以便更好地了解冰岛的冰川冰川 - 沃尔卡纳克危险潜力，同时同时学习世界上地质独特的部分。这项工作将加强现有的现有，并促进与该领域和分析实验室中的国内外科学家的新合作。它还将为社区参与和公共教育创造机会，并为6多名本科生提供严格的研究经验，其中大多数来自传统上代表性不足的背景。在中央火山，这一数量增加到约30％。 Vatnajökull下面的火山系统似乎相对于其亚赛的对应物而言，硅质物质很少。这可能是靠近山脊 - 倾斜交叉点的结果，或者（更可能）导致样本偏差的暴露不良的结果。由于硅岩浆具有比基本岩浆更大的爆炸性爆发和更大的相关危害的潜力，因此重要的是要了解它们在产品中可能扮演的角色，活跃的系统，从Vatnajökull遮盖的系统中。要研究的研究问题是：与Bárðarbunga，GrímsVötn和附近的Kverkfjöll相关的硅质材料在多大程度上？是从活跃的岩浆系统，较旧的卧室还是组合中收集的硅质材料？这些系统的硅材料的地球化学特性与冰岛其他地方的岩石记录中的硅化材料相比如何？在这个动态的裂谷羽状冰冰环境中存在哪些硅岩浆？这项研究中产生的数据将有助于绘制冰川硅材料（与活性火山系统和较旧卧室的硅材料相关的材料）的区域分布。 Evidence from nunatak and moraine rocks (major and trace elements; Hf, Nd, and Pb isotopes; petrography) and their accessory minerals (zircon: U-Th and U-Pb dates, O and Hf isotopes, trace elements; apatite: trace elements, volatiles) will make it possible to decipher the petrogenetic origins and evolution of silicone systems at Iceland’s most plume-affected,最活跃的中央火山。该奖项反映了NSF的法定任务，并通过评估诚实地支持了基金会的知识分子优点和更广泛的影响评论标准。