Relative velocity changes using ambient seismic noise at Okmok and Redoubt volcanoes, Alaska

PIS将提高探测导致阿拉斯加Okmok火山口和Redoubt火山活动性演化的前兆活动的能力，并增加对Redoubt岩浆储存复杂性的了解。他们将在雷杜特研究以下重要问题：(1)岩浆室的空间范围，(2)岩浆是否从一个初级岩浆室迁移到位于2至4.5公里深处的第二个岩浆库，(3)是否能够观测到最早可能在2009年事件前几个月观测到的对雷杜特地壳上部速度结构的时间扰动，反映出地壳中部深度的二氧化碳脱气，从而成为喷发的早期指标。在奥克莫克，他们将研究重要的问题，包括(1)2008年喷发前火山动荡的早期迹象和/或(2)喷发将在锥体D向西北方向喷发而不是预期的在锥体A喷发的早期迹象，(3)在2008年喷发前的几个月里，是否有迹象表明火山口内有浅层岩浆活动(1-3公里深)。提高对奥克莫克火山和雷杜布特火山活动前兆活动的探测的一个有希望的方法是利用这些火山记录的环境噪声进行地震干涉测量(特别是在2008年奥克莫克火山和2009年雷杜布特火山喷发前和喷发后)。奥克莫克和雷杜布特火山是阿留申弧区最活跃的两座火山，因此对生活在这些地区的人们、空中交通、当地渔业和当地石油生产设施构成重大威胁。这项研究将提高我们在Okmok和Redoubt探测导致激进主义的前兆活动的能力，并增加我们对Redoubt磁存储的复杂性的理解。这项拟议的研究还将拓宽早期职业女性科学家的经验。

The PIs will improve the ability to detect precursory activity leading to activevolcanism at both Okmok caldera and Redoubt volcano, Alaska, as well as increase understanding ofthe complexity of magma storage at Redoubt. They will investigate important questions at Redoubtregarding (1) the spatial extent of the magma chamber, (2) if magma migrates from a primary magmachamber to a second magma reservoir located somewhere between 2 and 4.5 km depth, (3) if temporaryperturbations to the upper crustal velocity structure of Redoubt, reflecting CO2 degassed at mid-crustaldepths, can be observed, possibly as early as several months prior to the 2009 event, thus serving as anearly indicator of the eruption. At Okmok, they will examine important questions including (1) theexistence of early signs of volcanic unrest preceding the 2008 eruption and/or (2) early indicators that theeruption would emanate NW of Cone D instead of an expected eruption at Cone A, (3) if there wereindications of shallow magma movement (1-3 km depth) within the caldera in the months leading up tothe 2008 eruption. One promising approach to improve detection of precursory activity leading to activevolcanism at Okmok and Redoubt is to carry out seismic interferometry using ambient noise recorded atthese volcanoes (specifically pre- through post-eruption for the 2008 Okmok and 2009 Redoubteruptions).Okmok and Redoubt are two of the most active volcanoes in the Aleutian Arc and, assuch, pose major hazards to people living within these regions, air traffic, local fisheries, and local oilproduction facilities. This study will improve our ability to detect precursory activity leading to activevolcanism at both Okmok and Redoubt as well as increase our understanding of the complexity of magmastorage at Redoubt. The proposed study will also broaden the experience of an early career femalescientist.