| 项目编号: | 1520875
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| 项目名称: | High-resolution studies of seismicity and scattered wave imaging beneath Mt. St. Helens |
| 作者: | Brandon Schmandt
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| 承担单位: | University of New Mexico
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| 批准年: | 2014
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| 开始日期: | 2015-07-01
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| 结束日期: | 2018-06-30
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| 资助金额: | USD219999
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| 资助来源: | US-NSF
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| 项目类别: | Continuing grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Earth Sciences
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| 英文关键词: | mt. st. helens
; micro-seismicity
; project
; 3-d
; mirco-seismicity
; wave imaging
; detection
; seismic wave field
; moho imaging
; seismic imaging
; abundant local seismicity
; reflection imaging
; hybrid active/passive source 3-d study
|
| 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. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/94181
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Brandon Schmandt. High-resolution studies of seismicity and scattered wave imaging beneath Mt. St. Helens. 2014-01-01.
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