RAPID: Probing magma plumbing and seismicity beneath Mt. St. Helens with modern exploration industry seismometers

RAPID：利用现代勘探行业地震仪探测圣海伦斯山下方的岩浆管道和地震活动

• 批准号: 1445937
• 负责人: Brandon Schmandt
• 金额: $ 4.94万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-15 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1445937&HistoricalAwards=false
• 关键词: RAPID; Probing; magma; plumbing; seismicity

It is notoriously difficult to construct 3-D images of the magma plumbing systems that exist beneath volcanoes because uncovering the details of the magma system requires highly dense observations of a wide range of seismic events. At the same time, understanding these magma systems is vital because they play key roles in determining the nature and severity of hazards posed by volcanoes like Mt. St. Helens. This project is using modern exploration industry seismometers to provide dense observations of explosions and natural earthquakes in the rugged terrain around Mt. St. Helens. The data are being delivered to the IRIS Data Management Center, thereby providing the seismic community experience with a potential type of next-generation seismic array for structure and source studies. A team of undergraduate and graduate students, a postdoctoral scholar, and the PI from University of New Mexico are deploying the instruments in collaboration with an exploration industry service company (NodalSeismic of Long Beach, California). Students are gaining the opportunity to participate in a large multi-institution field campaign at Mt. St. Helens and experience with the operations of an innovative service company. Nearly all the UNM participants are also using the data in a new seismology class for senior undergraduates and graduate students at UNM, and undergraduate participants are also using the data for senior research projects. This project is deploying about 1,000 Fairfield Nodal seismometers (nodes) to record continuously for two weeks in a dense array within about 15 km of Mt. St. Helens in order to obtain detailed 3-D seismic sampling of the magma plumbing system and surrounding crust. The deployment is leveraging 24 controlled sources detonated by the NSF-funded iMUSH project, and the nodes are providing 2 weeks of continuous recording of frequent local seismicity and ambient noise. Deployment of 1,000 nodes in the inner 15 km around MSH is greatly improving opportunities for 3-D imaging of the magma plumbing system with wave-field based methods and enabling high-resolution constraints on locations and mechanisms of seismicity that could provide insight into melt/fluid transport processes beneath arc volcanoes.

众所周知，构建火山下方岩浆管道系统的 3D 图像非常困难，因为揭示岩浆系统的细节需要对各种地震事件进行高密度观测。 与此同时，了解这些岩浆系统至关重要，因为它们在确定圣海伦斯火山等火山造成的危害的性质和严重程度方面发挥着关键作用。 该项目使用现代勘探工业地震仪对圣海伦斯山周围崎岖地形的爆炸和自然地震进行密集观测。这些数据将被传送到 IRIS 数据管理中心，从而为地震界提供用于结构和震源研究的潜在下一代地震阵列类型的经验。由本科生和研究生、博士后学者和新墨西哥大学的 PI 组成的团队正在与勘探行业服务公司（加利福尼亚州长滩的 NodalSeismic）合作部署这些仪器。学生将有机会参加圣海伦斯山的大型多机构实地活动，并体验创新服务公司的运营。几乎所有新墨西哥大学参与者也在新墨西哥大学高年级本科生和研究生的新地震学课程中使用这些数据，本科生参与者也在高级研究项目中使用这些数据。该项目正在圣海伦斯山约 15 公里范围内部署约 1,000 个 Fairfield Nodal 地震仪（节点），在密集阵列中连续记录两周，以获得岩浆管道系统和周围地壳的详细 3D 地震采样。该部署利用了 NSF 资助的 iMUSH 项目引爆的 24 个受控源，节点可连续记录两周的频繁局部地震活动和环境噪声。在 MSH 周围 15 公里内部署 1,000 个节点极大地提高了使用基于波场的方法对岩浆管道系统进行 3D 成像的机会，并实现了对地震活动位置和机制的高分辨率约束，从而可以深入了解熔体/弧火山下的流体输送过程。