Collaborative Research: An integrated seismic-geodetic study of active magmatic processes at Sierra Negra volcano, Galapagos Islands

合作研究：加拉帕戈斯群岛塞拉内格拉火山活动岩浆过程的综合地震大地测量研究

• 批准号: 0838493
• 负责人: Falk Amelung
• 金额: $ 23.15万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-15 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0838493&HistoricalAwards=false
• 关键词: Collaborative; Research; integrated; seismic; geodetic

Intellectual MeritsOcean island volcanoes initiate and grow over time periods of 105 to 106 years, requiring a long-lived magmatic plumbing system to transport magma from the mantle to the surface. Only a fraction of the magma, however, is erupted; magma is stored in crustal magma chambers, or trapped near the crust-mantle boundary. These magma intrusions grow the crust, and change the state of stress. The increase in pressure accompanying magma intrusion inflates the volcanic edifice, triggering earthquakes and eruptions. The geometry of the magma chambers and conduits, therefore, is fundamental to the development of predictive models of volcano deformation and eruption.Our integrated seismic and geodetic data acquisition and modelling project aims to image the magma plumbing system beneath the most rapidly deforming hotspot volcano system in the world: Sierra Negra volcano in the Galapagos Archipelago. Existing SAR data provide high-resolution images of surface deformation over broad regions, and GPS provides continuous time series of vertical and horizontal deformation. We cannot, however, differentiate between the basaltic volcano growth models without complementary seismic information on the distribution and mechanisms of seismic strain, as well as the crust and upper mantle structure. We will deploy and maintain 16 broadband seismometers for two years, recording seismic waves from local and distant earthquakes to illuminate the magmatic plumbing system and state of stress within the lithosphere beneath Sierra Negra volcano to understand the stress interaction between shallow magma intrusion, extrusion, and intra-caldera faulting processes. The anticipated results are a new 4D model of Sierra Negra?s shallow and deep magmatic system that satisfies seismic and geodetic observations, and is constrained by earthquake locations, focal mechanisms, wavespeed and ambient noise tomography, seismic anisotropy, receiver function estimates of sill and Moho depths, and existing petrological data. We will determine the time-varying state of stress within and around the volcano in response to magma intrusion and withdrawal, including the dynamic relationship between trapdoor faulting and magma intrusionBroader Significance and ImportanceOcean island volcanoes initiate and grow over time periods of 105 to 106 years, requiring a long-lived magmatic plumbing system to transport magma from the mantle to the surface. Only a fraction of the magma, however, is erupted; magma is stored in crustal magma chambers, or trapped near the crust-mantle boundary. These magma intrusions grow the crust, and change the state of stress. The increase in pressure accompanying magma intrusion inflates the volcanic edifice, triggering earthquakes and eruptions. Sierra Negra volcano in the Galapagos Archipelago is the most rapidly deforming of these ocean island volcanoes. Continuous monitoring of earthquake and surface deformation is vital to deduce the geometry of the magma chambers and conduits, and the physical changes to the volcano edifice itself. These data, in turn, inform predictive models of volcano deformation and eruption worldwide.Our continuous seismic, satellite, GPS monitoring and modeling project has been designed to maximize the broader impacts, which fall into 3 areas: volcanic hazards, education, and international collaboration. Nearly a million people live on active basaltic volcanoes; understanding the relationship between magma supply, state of stress and eruptions is vital for hazard assessment, including the potential for tsunami-generating flank instabilities. The baseline provided by the geodetic and seismic monitoring is essential to development of a volcanic hazard mitigation program in the Galápagos Archipelago, and other basaltic volcanoes worldwide.This project will provide a collaborative opportunity for US undergraduate, graduate, and Ecuadorian students. Students from both countries will benefit from experience with the realities of field-based geophysics, gaining valuable skills in seismology and geodesy that can be translated to the workplace or advanced degree programs.This work is co-funded by the Geophysics and Geochemistry Programs and the Americas Program of the Office of International Science and Engineering.

知识分子的出色岛岛火山在105至106年的时间内启动和生长，需要长寿命的岩浆管道系统将岩浆从地幔运输到地面。然而，只爆发了岩浆的一小部分。岩浆存储在地壳岩浆腔室中，或被困在地壳竖井边界附近。这些岩浆侵入会增加外壳，并改变压力状态。压力参与岩浆入侵的增加会膨胀火山大厦，引发地震和爆发。因此，岩浆腔和导管的几何形状是火山变形和喷发预测模型的发展至关重要的。我们综合的地震和大地测量数据采集和建模项目旨在为世界上最快速变形的热点火山系统形象岩浆管道系统：加拉帕戈斯群岛上的塞拉利昂·内格拉火山。现有的SAR数据提供了广泛区域表面变形的高分辨率图像，而GPS提供了垂直和水平变形的连续时间序列。但是，如果没有完整的地震信息，我们无法区分玄武岩火山生长模型，有关地震菌株的分布和机制，以及地壳和上地幔结构。我们将在两年内部署和维护16个宽带地震仪，记录从局部和遥远的地震的地震波，以照亮岩浆管道系统和岩石层中岩石层内的压力状态，以了解浅层岩浆入侵，或越甲壳虫内的浅层岩浆入侵，expersevera和caldera caldera caldera calteces的压力相互作用。预期的结果是塞拉内格拉（Sierra Negra）的新型4D模型，可满足地震和地球测量的浅层岩浆系统，并受地震位置，焦点机制，波动机制，环境噪声层析造影，地震向向障碍，地震向向异常，接收器功能估计和MOHO DEPTHS和现有Petrology Data的限制。 We will determine the time-varying state of stress within and around the volcano in response to magma intrusion and withdrawal, including the dynamic relationship between trapdoor faulting and magma intrusionBroader Significance and ImportanceOcean island volcanoes initiate and grow over time periods of 105 to 106 years, requiring a long-lived magmatic plumbing system to transport magma from the mantle to the surface.然而，只爆发了岩浆的一小部分。岩浆存储在地壳岩浆腔室中，或被困在地壳竖井边界附近。这些岩浆侵入会增加外壳，并改变压力状态。进行岩浆入侵的压力的增加膨胀了火山大厦，引发了地震和喷发。加拉帕戈斯群岛的塞拉尼格拉山脉是这些海洋岛火山最快的变形。对地质和表面变形的连续监测对于推断岩浆和导管的几何形状以及火山大厦本身的物理变化至关重要。这些数据反过来为世界范​​围内火山变形和喷发的预测模型提供了信息。我们连续的地震，卫星，GPS监测和建模项目旨在最大程度地发挥更广泛的影响，这些影响属于3个领域：火山危害，教育和国际合作。将近一百万人生活在活跃的基本火山上；了解岩浆供应，压力和喷发状态之间的关系对于危害评估至关重要，包括可能产生海啸的侧面不稳定性。大地测量监测提供的基线对于在加拉帕戈斯群岛的火山危害缓解计划以及全球其他玄武岩火山的开发至关重要。该项目将为我们的本科生，研究生和厄瓜多尔学生提供协作机会。来自两国的学生将从基于现场的地球物理的现实经验中受益，获得地震学和地理学方面的价值技能，这些技能可以转化为工作场所或高级学位课程。这项工作由地球物理学和地球化学计划以及国际科学与工程办公室的美洲计划共同资助。