| 项目编号: | 1547064
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| 项目名称: | Collaborative Research: Rheology of asthenosphere in the Kuril-Kamchatka subduction zone from postseismic GPS observations after great earthquakes |
| 作者: | Jeffrey Freymueller
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| 承担单位: | University of Alaska Fairbanks Campus
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| 批准年: | 2016
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| 开始日期: | 2016-06-15
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| 结束日期: | 2018-05-31
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| 资助金额: | 30713
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| 资助来源: | US-NSF
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| 项目类别: | Standard 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: | project
; earthquake
; datum
; post-earthquake
; kuril-kamchatka subduction zone
; subduction-zone seismic activity
; post-earthquake gp measurement
; subduction interface
; stress-dependent rheology
; kuril earthquake
; non-linear rheology
; imminent large earthquake
; long-term earthquake cycle
; kuril subduction zone
; disastrous earthquake
; nonlinear mantle rheology
|
| 英文摘要: | The project relates to the region of the Kuril subduction zone in the northwest Pacific Ocean subject to disastrous earthquakes. In 2006?2007, a doublet of great (MW > 8) earthquakes partly ruptured one of the most conspicuous gaps in subduction-zone seismic activity. An immediate focus of this project is to acquire post-earthquake GPS measurement spanning the time period 2007?2016. These data will allow scientists to better understand the long-term earthquake cycle and will be important for understanding seismic hazards here and in other similar settings. This project will continue and strengthen collaboration between US universities and institutions of the Russian Academy of Sciences. The data provided by the project will be available for use by the broad scientific community.
The complete 10-year-long data set is required to address fundamental problems: How much of the strain built up from subduction of the Pacific plate beneath the North American plate (the Sea of Okhotsk) has been released in the 2006 and 2007 Kuril earthquakes coseismically and postseismically? Is it possible to explain postseismic surface deformation at the Kuril-Kamchatka subduction zone with the linear viscous mantle or is a stress-dependent rheology required? These problems are especially important after the giant 2011 MW 9.0 Tohoku (Japan) earthquake, which made the scientists question the validity of precursors of imminent large earthquakes: location of seismic gaps (spatial gaps in seismic activity) and location of asperities (patches of high frictional locking at a subduction interface). Observations of postseismic deformation of this length are rare and can significantly improve understanding of the rheology of the mantle. Preliminary results of the 3-D modeling of viscoelastic relaxation now include the effect of slab geometry for linear and nonlinear mantle rheologies with a focus on matching station velocities observed five years and later. The proposed work will extend the modeling efforts based on a significantly increased interval of the data (>20% longer). This relatively late stage data is critical in testing the hypothesis of non-linear rheology. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/92059
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
|