Understanding Dike Propagation Through Comparison of High-fidelity Coupled Fracture and Fluid Flow Models and Field Observations

通过比较高保真耦合裂缝和流体流动模型以及现场观测来了解堤坝的扩展

• 批准号: 2333837
• 负责人: Paul Segall
• 金额: $ 52.5万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2333837&HistoricalAwards=false
• 关键词: Understanding; Dike; Propagation; Through; Comparison

Prior to volcanic eruptions magma rises through the crust, most commonly within narrow fractures known as “dikes.” Dike ascent is often accompanied by small earthquakes and deformation of the ground surface which can be detected by ground-based, and in some cases space-based sensors. Not all dikes lead to eruptions; in some cases, they stall and the magma solidifies without erupting. To properly interpret seismic and deformation signals and provide societally-relevant eruption warnings, we must understand the physical and chemical processes that control how rapidly dikes ascend, the paths they take, and whether or not they make it to the surface. These processes include resistance and motion of the solid rock outside the dike, the flow of magma within the dike, fracture of the crust at the dike tip, and possible solidification of the magma as it cools during its journey toward the surface - all of which are interdependent. Segall, Lew, and their team will use sophisticated computational techniques together with ground deformation and earthquake data to model dike ascent in Hawaii, and to develop guidelines for using such data to forecast eruptions in Hawaii and at similar volcanoes worldwide. This research will address one of the Grand Challenges in the National Academies ERUPT report to advance physics-based eruption forecasting. Accurate, high-fidelity models of dike propagation are key to understanding precursors to many eruptions and will ultimately facilitate forecasting at volcano observatories worldwide.This project will leverage advances in computational methods that allow the numerical grid to adapt to the changing shape of the dike as it grows. These and other advances will allow them to address: the conditions (magma viscosity, background temperature gradient, reservoir pressure, volume, and compressibility) that permit a dike to reach the earth's surface; the time-dependent surface deformations and seismicity-inducing stress perturbations that could be used in physics-based eruption forecasting; and the factors that determine whether deep dikes are focused toward or bypass crustal reservoirs. Computed dike ascent histories and predicted surface deformation will be compared to observations of deformation and seismicity that precedes some eruptions, as well as with laboratory analog experiments.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.

在火山喷发之前，岩浆会穿过地壳上升，最常见的是在被称为“岩脉”的狭窄裂缝内。并非所有岩堤都会导致喷发；在某些情况下，它们会停滞并且岩浆会凝固而不会喷发，从而正确解释地震和变形信号并提供与社会相关的喷发。警告，我们必须了解控制堤坝上升速度的物理和化学过程、它们所采取的路径以及它们是否到达地表这些过程包括堤坝外固体岩石的阻力和运动、水流的流动。岩脉内的岩浆、岩脉尖端地壳的破裂，以及岩浆在流向地表过程中冷却时可能发生的凝固——所有这些都是相互依赖的，Segall、Lew 和他们的团队将使用复杂的计算技术。地面变形与地震这项研究将解决国家科学院 ERUPT 报告中的重大挑战之一，以推进基于物理的喷发预测。准确、高保真度的堤坝传播模型是了解许多火山喷发前兆的关键，并将有助于全球火山观测站的最终预测。该项目将利用计算方法的进步，使数值网格能够适应这些和其他进步将使他们能够解决：允许岩浆到达地球表面的条件（岩浆粘度、背景温度梯度、储层压力、体积和压缩性）；可用于基于物理的喷发预测的随时间变化的表面变形和地震诱发的应力扰动；以及确定深岩脉是否集中于或绕过地壳储层的因素。预测的地表变形将与一些喷发前的变形和地震活动的观测结果以及实验室模拟实验进行比较。该奖项授予 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。