Seismo-Acoustic Dynamics of Silicic Dome Eruptions

研究人员提议对厄瓜多尔的两座安第斯火山瓜瓜皮钦查和通古拉华进行研究，因为它们表现出相对频繁的爆炸事件(包括火山碎屑和火山岩浆)，并提供了无与伦比的实地研究机会。皮钦查的活动类似于位于温岑、默拉皮、贝兹明尼和蒙塞拉特的活火山活动。由于通古拉瓦海拔陡峭，对巴诺斯市构成危险，因此极其危险。该项目旨在对一般的硅质火山活动特别是这两座火山进行现场观测和开发新的模型。为了了解硅质穹顶火山脱气的控制特征，将安装新的仪器，包括宽带地震和次声波传感器，以监测斯特龙博利亚型爆炸活动。完成高保真观测所需的技术，包括硬件和软件，将转移给基多地质研究所的厄瓜多尔同事。利用次声麦克风和宽带地震仪阵列记录的弹性和声能辐射将用于评估爆炸能量释放、地面和大气的相对能量分配以及爆炸源位置。数字化视频记录将用于用气体羽流喷射速度校准次声产生，并核实震源、时间、震源和位置。将开发穹顶爆炸性脱气的物理模型，并将其与粘度较低的开放式岩浆系统(Stromboli、Karymsky、Arenal、Erebus)进行比较，以便次声和地震工具可以用于远程预测所有类型的火山爆炸的脱气行为。这项建议的主要影响将是：1)开发适用于以前未探索的火山活动的新火山爆炸模型；2)对厄瓜多尔危险火山的地震/声学信号进行新的观察；3)厄瓜多尔和美国研究人员在减少活跃火山灾害方面建立强有力的合作；4)在危险火山发生大型坍塌事件之前对危险火山进行危险评估。

The investigators propose a study of two Andean volcanoes, Guagua Pichincha and Tungurahua, Ecuador, because they exhibit relatively frequent explosive events (both pyroclastic and phreato-magmatic) and offer unparalleled access for field study. Activity at Pichincha is an analogue for active volcanism at: Unzen, Merapi, Bezmianny, and Monserrat. Tungurahua is extremely hazardous due to its steep elevation and danger posed to the city of Banos. The project is aimed at field observations and developing new models for silicic volcanism in general and these two volcanoes specifically.To understand the controlling features of volcanic degassing at silicic domes new instrumentation, including broadband seismic and infrasonic acoustic sensors will be installed to monitor the Strombolian-type explosion activity. The technology required to accomplish high fidelity observations, including hardware and software, will be transferred to Ecuadorian Colleagues at the Instituto Geofisica in Quito. Elastic and acoustic energy radiation recorded with arrays of infrasonic microphones and broad-band seismometers will be used to assess the explosive energy release, relative energy partitioning into the ground and atmosphere, and explosion source location. Digitized video records will be used to calibrate infrasound generation with gas plume ejection velocities and verify source time origin and locations. Physical models of explosive degassing at domes will be developed and compared to lower-viscosity, open-vent magmatic systems (Stromboli, Karymsky, Arenal, Erebus), so that infrasonic and seismic tools can be used to remotely predict degassing behavior for all types of volcanic explosions. The major impact of this proposal will be 1) the development of new volcano explosion models applied to previously unexplored volcanic activity, 2) new observations of seismo/acoustic signals at hazardous volcanoes in Ecuador, and 3) establishment of a strong collaboration between Ecuadorian and U.S. researchers on active volcanic hazard reduction, 4) assessment of hazard prior to large collapse events on dangerous volcanoes.This project is co-sponsored by the Americas Program in the Office Of International Science And Engineering.