High-resolution studies of seismicity and scattered wave imaging beneath Mt. St. Helens

GSTDTAP

项目编号	1520875
	High-resolution studies of seismicity and scattered wave imaging beneath Mt. St. Helens
	Brandon Schmandt
主持机构	University of New Mexico
项目开始年	2015
	2015-07-01
项目结束日期	2017-06-30
资助机构	US-NSF
项目类别	Continuing grant
项目经费	137453(USD)
国家	美国
语种	英语
英文摘要	Subduction zone magmatic systems, such as in the Cascades Arc of the northwestern U.S., underlie potential natural hazards near major cities and are considered the primary agents of continental crust production. The significance of these systems on both human and geological time scales merits a greater understanding of how they function. Seismic imaging of the plumbing structure of magmatic systems and detection of earthquakes can illuminate active and formerly active melt pathways and reservoirs. However, the complexity of seismic wave fields in volcanic regions challenges efforts to map the 3-D structure of magma plumbing systems as well as efforts to detect, locate, and determine the mechanisms of the diverse range of earthquakes that occur there. The challenges largely reflect observational limitations. Typical seismograph networks for observing volcanoes such as Mt. St. Helens are composed of ~10 long-term seismographs. This project will analyze data from a short-term, two week, deployment of 900 seismographs within 12 km of the summit crater of Mt. St. Helens. The dense seismic data will be used to identify the fine scale spatial and temporal distribution of micro-seismicity beneath Mt. St. Helens and determine how that seismicity is linked to the 3-D prevalence of fluids and cooled intrusions in the crust and uppermost mantle. The project aims to resolve the 3-D magma plumbing beneath Mt. St. Helens with scattered wave imaging and tomography of the uppermost 10-15 km. A major component of the project will be testing and advancing methods for automated detection of mirco-seismicity using continuous data from large numbers of sensors, each with potentially high noise levels that prevent detection with single-station methods. Deeper melting and deformation processes will also be investigated through reflection imaging of the sub-arc Moho and investigation of the prevalence of deep long period earthquakes in the lower crust. Moho imaging will exploit both controlled sources and abundant local seismicity. Data products will be made publicly available, and advancing hybrid active/passive source 3-D studies with dense seismograph arrays is likely to be valuable for the seismology community in the near future. The project will support the training of a graduate student, an undergraduate intern, and a postdoctoral fellow.
来源学科分类	Geosciences - Earth Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/68151
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Brandon Schmandt.High-resolution studies of seismicity and scattered wave imaging beneath Mt. St. Helens.2015.