| 项目编号: | 1344993
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| 项目名称: | Earthquake nucleation on faults with rate- and state-dependent friction: a dynamical system's approach to instability |
| 作者: | Robert Viesca
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| 承担单位: | Tufts University
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| 批准年: | 2013
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| 开始日期: | 2014-02-01
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| 结束日期: | 2018-01-31
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| 资助金额: | USD214199
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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: | fault
; slip instability
; earthquake
; nucleation
; nucleation process
; fault property
; fault friction
; development
; prevalent slip rate
; laboratory friction experiment
; preferential nucleation site
; novel approach
; dynamical system context
; earthquake science
; dynamic rupture
; nonlinear dynamical system
; dynamic fault rupture
; interseismic slip rate
; rate-strengthening behavior
; fault gouge composition
; early warning system
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| 英文摘要: | An outstanding problem in earthquake science is how fault slip transitions from slow creep or a nearly locked state to an earthquake-generating dynamic rupture of the fault. Fundamental questions are how an evolving fault friction allows for and determines the development of a slip instability that ultimately nucleates dynamic rupture; how conditions on the fault affect that development; and what are the consequences for the seismic cycle and the discernment of earthquakes at their earliest stages. There is societal and scientific interest in understanding how earthquakes start. Without an understanding of how dynamic fault rupture is initiated, it is unlikely we will reliably understand the origin of the earliest seismic signals that are crucial for early warning systems.
Through recent work, we have developed a transformative understanding of slip instability formation on interfaces of elastic bodies whose friction follows the prevalent slip rate- and state- dependence indicated by laboratory friction experiments at low, interseismic slip rates. Treating a slipping fault as a nonlinear dynamical system, we have found the manner by which earthquake-nucleating slip instabilities develop on such interfaces. In the dynamical system context, the development corresponds to fixed-point attraction. Our novel approach has opened up new avenues to address, in rigorous detail, several of the fundamental issues concerning nucleation: whether preferential nucleation sites can exist and, if identified, how they may be expressed in the seismic cycle and what they may imply about the distribution of the local intensity of rate-weakening or rate-strengthening behavior; whether the nucleation process may be a chaotic one, such that small changes in initial conditions at the onset of a slip instability may result in large differences in the moments immediately preceding dynamic rupture; and how spatial variations of fault properties and conditions (such as fault gouge composition and thickness, ambient temperatures and pore fluid pressures) control nucleation. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/97389
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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: | |
Robert Viesca. Earthquake nucleation on faults with rate- and state-dependent friction: a dynamical system's approach to instability. 2013-01-01.
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