Probing the Multiscale Nature of Crustal Magma Transport

探索地壳岩浆输送的多尺度性质

• 批准号: 1143623
• 负责人: Leif Karlstrom
• 金额: $ 17万
• 依托单位: Karlstrom Leif
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1143623&HistoricalAwards=false
• 关键词: Probing; Multiscale; Nature; Crustal; Magma

Dr. Leif Karlstrom has been granted an NSF Earth Sciences postdoctoral fellowship to carry out a research and education plan at Stanford University. He will investigate magma transport processes in the crust on two different scales through modeling of volcanic tremor and statistical inference of arc-scale eruption patterns. The tremor work aims to identify available mechanisms for the origin of seismicity during volcanic eruptions, and will examine long period seismic signatures of different eruption styles with a coupled fluid flow and elastodynamic numerical model. The larger scale aspect of this work will test models of magmatic plumbing with Quaternary eruptions in the Cascades arc. Network inference techniques and Bayesian statistics will be applied to a newly compiled dataset of recent volcanism throughout the Cascades. The goal of this study is to test for the degree to which magma transport is controlled by dynamic internal organization versus external forcing (glaciation, spatially variable tectonic stresses).Magma transport is relevant both for understanding Earth history and volcano-human interactions, but it is largely inaccessible to direct observation. As a result, the mechanics of rising and cooling magmas that generate episodic volcanism are poorly constrained. This work probes the deep structure of volcanoes by modeling patterns of radiated seismic waves during eruptions, and using statistical inference techniques to probe the structure of magma plumbing throughout the Cascades volcanic arc. These studies ask the general question: to what extent can theoretical models represent or predict indirect, remote observations? This question has important implications for the degree to which models and data can be synthesized to interpret the geologic record and assess volcanic hazards. Educational activities associated with this project include leading a field trip to Lassen National Park and co-teaching a course on physical volcanology at Stanford.

Leif Karlstrom 博士已获得美国国家科学基金会地球科学博士后奖学金，在斯坦福大学开展研究和教育计划。他将通过火山震颤建模和弧尺度喷发模式的统计推断，研究两种不同尺度的地壳中岩浆输送过程。地震工作旨在确定火山喷发期间地震活动起源的可用机制，并将通过耦合流体流和弹性动力学数值模型检查不同喷发类型的长期地震特征。这项工作的更大范围将测试喀斯喀特弧第四纪喷发的岩浆管道模型。网络推理技术和贝叶斯统计将应用于新编译的整个喀斯喀特近期火山活动的数据集。本研究的目的是测试岩浆输送受动态内部组织与外部强迫（冰川作用、空间变化的构造应力）控制的程度。岩浆输送对于理解地球历史和火山与人类的相互作用都相关，但它很大程度上无法直接观察。因此，产生间歇性火山活动的岩浆上升和冷却的机制很少受到限制。这项工作通过模拟喷发期间的辐射地震波模式来探测火山的深层结构，并使用统计推断技术来探测整个喀斯喀特火山弧的岩浆管道结构。这些研究提出了一个普遍问题：理论模型可以在多大程度上代表或预测间接、远程观测？这个问题对于综合模型和数据来解释地质记录和评估火山灾害的程度具有重要意义。与该项目相关的教育活动包括领导对拉森国家公园的实地考察以及在斯坦福大学共同教授物理火山学课程。