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

众所周知，构建火山下岩浆管道系统的3D图像是非常困难的，因为要揭示岩浆系统的细节，需要对广泛的地震事件进行高度密集的观测。 与此同时，了解这些岩浆系统是至关重要的，因为它们在确定火山造成的危害的性质和严重性方面发挥着关键作用。圣海伦。 该项目正在使用现代勘探工业地震仪，在山周围崎岖的地形中提供爆炸和自然地震的密集观测。圣海伦。这些数据正被送到IRIS数据管理中心，从而为地震界提供了一种用于结构和震源研究的潜在的下一代地震阵列。一个由本科生和研究生组成的团队、一名博士后学者以及来自新墨西哥州大学的PI正在与一家勘探行业服务公司（加州长滩的NodalSeismic）合作部署这些仪器。学生们有机会参加一个大型的多机构实地活动在山。圣海伦斯和经验与一个创新的服务公司的运作。几乎所有的UNM参与者也在UNM的高年级本科生和研究生的新地震学课程中使用这些数据，本科生参与者也在使用这些数据进行高级研究项目。该项目部署了大约1,000个费尔菲尔德节地震仪（节点），在距离Mt.约15公里的密集阵列中连续记录两周。为了获得岩浆管道系统和周围地壳的详细三维地震取样，该部署利用了由NSF资助的iMUSH项目引爆的24个受控源，这些节点提供了为期2周的频繁的当地地震活动和环境噪声的连续记录。在MSH周围15公里内部署1，000个节点，极大地改善了利用基于波场的方法对岩浆管道系统进行三维成像的机会，并实现了对地震活动位置和机制的高分辨率限制，从而可以深入了解弧火山下的熔体/流体输送过程。

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.