Collaborative Research: Axial 3-D - Exploring the linkages between complex magma chamber structure, caldera dynamics, fluid pathways and hydrothermal venting

这项研究将获得位于华盛顿州近海约450公里处的水下Axial火山内部结构的高分辨率三维地图。这些数据将解决一个古老的问题，“火山到底是如何运作的？”轴向火山是获取地下岩浆室信息的理想地点，因为那里已经收集了许多其他数据。已经详细绘制了轴心火山的表面特征图，并通过海洋观测站倡议海底观测站对火山进行了实时监测。获得岩浆室结构的图像将补充现有数据和OOI提供的实时数据，并允许更好地了解Axial火山如何工作以及何时可能喷发。这项研究将促进世界各地对陆地和水下火山的了解。该项目为研究生和早期职业科学家提供培训。对数据的访问将是开放的。该项目将完成对R/V Marcus Langseth上的轴向火山和相关裂谷轴线的全面三维多道地震调查。此外，还将收集8条15公里长的源-接收器偏移距二维反射剖面，以研究岩浆输送的深层结构。已经开发了一套复杂的地震成像工具，侧重于在水下火山地形中收集的多通道地震数据。这一算法方法已在许多海洋环境中以2-D方式使用，迄今在Axial火山取得了最大的成功，在那里已经清楚地拍摄到了下面岩浆室的屋顶和底部，以及连接岩浆室和附近热液喷发区的上地壳的裂缝/管道。尽管取得了这一成功，但Axial火山本质上是三维的，因此需要一种三维方法来绘制深部岩浆管道系统与海底喷发动力学之间的复杂联系。例如，需要这种方法来理解(1)3-D裂隙组如何与上地壳中的岩浆膨胀/撤退、裂谷和重力扩展/坍塌相关联；(2)不同数量的熔体/泥浆的复杂岩浆体的几何形状和相互联系；(3)内部结构与海底观测数据(如热液场和熔岩流)之间的关系。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This study will obtain a high-resolution three-dimensional map of the internal structure of the underwater Axial Volcano, which is located about 450 km offshore of Washington State. These data will address the age-old question, "How do volcanoes really work?". Axial Volcano is an ideal location to obtain information on the underground magma chamber because a lot of other data have already been collected there. The surface features of Axial Volcano have been mapped in detail and the volcano is monitored in real-time through the Ocean Observatory Initiative Seafloor (OOI) Observatory. Obtaining an image of the magma chamber structure will complement existing data and the real-time data being provided by OOI, and allow a much better understanding of how Axial Volcano works and when it might erupt. This study will advance understanding of volcanoes both on land and underwater world wide. The project provides training for graduate students and early career scientists. Access to the data will be open. This project will complete a comprehensive 3-D multichannel seismic survey of Axial Volcano and associated rift axes aboard the R/V Marcus Langseth. In addition, eight 15-km-long source-receiver offset 2-D reflection profiles will be collected to look at deep-seated structure of magma delivery. A sophisticated set of seismic imaging tools focused on multichannel seismic data collected in underwater volcanic terrains has been developed. This algorithm approach has been used in a number of marine environments in 2-D, with the greatest success thus far at Axial Volcano, where the roof and floor of the underlying magma chamber have been clearly imaged, along with fractures/conduits in the upper crust connecting the magma chamber to nearby hydrothermal vent fields. Despite this success, Axial Volcano is inherently 3-D in nature, thus requiring a 3-D approach to map the complex connections between the magma plumbing system at depth with eruption dynamics at the seafloor. For example, this approach is needed to understand (1) how 3-D fracture sets are associated with magma inflation/withdrawal, rifting, and gravitational spreading/collapse in the upper crust; (2) the geometry and interconnection of complex magma bodies of varying amounts of melt/mush; (3) the relationship between internal structure and seafloor observables such as hydrothermal fields and lava flows.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.