DOI: 10.1016/j.epsl.2019.115869
论文题名: Modelling fluid flow in complex natural fault zones: Implications for natural and human-induced earthquake nucleation
作者: Snell T. ; De Paola N. ; van Hunen J. ; Nielsen S. ; Collettini C.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 530 语种: 英语
中文关键词: earthquake nucleation
; failure
; fault
; fluid pressure
; simulation
英文关键词: Computer system recovery
; Deformation
; Earthquakes
; Faulting
; Nucleation
; Phase meters
; Strain measurement
; Structural geology
; Earthquake early warning systems
; Earthquake forecasting
; Earthquake nucleation
; Earthquake recurrence intervals
; Fault zone architecture
; Fault-zone permeabilities
; Fluid pressures
; simulation
; Flow of fluids
; active fault
; computer simulation
; deformation mechanism
; early warning system
; earthquake mechanism
; earthquake precursor
; earthquake prediction
; earthquake recurrence
; fault zone
; flow modeling
; fluid flow
; fluid pressure
; induced seismicity
; numerical model
; seismicity
; Apennines
; Italy
英文摘要: Pore fluid overpressures in active fault systems can drive fluid flow and cause fault weakening and seismicity. In return, deformation accommodated by different modes of failure (e.g. brittle vs. ductile) also affects fault zone permeability and, hence, fluid flow and pore fluid pressure distribution. Current numerical simulation techniques model how fluid flow controls fault reactivation and associated seismicity. However, the control exerted by pore fluid pressure on the transition from slow aseismic fault sliding to fast seismic sliding, during the earthquake nucleation phase, is still poorly understood. Here, we model overpressured, supercritical CO2 fluid flow in natural faults, where non-linear, complex feedback between fluid flow, fluid pressure and fault deformation controls the length of the nucleation phase of an earthquake and the duration of the interseismic period. The model setup is an analogue for recent seismic source events in the Northern Apennines of Italy (e.g. Mw 6.0 1997-98 Colfiorito and Mw 6.5 2016 Norcia earthquakes). Our modelling results of Darcy fluid flow show that the duration of the nucleation phase can be reduced by orders of magnitude, when realistic models of fault zone architecture and pore pressure- and deformation-dependent permeability are considered. In particular, earthquake nucleation phase duration can drop from more than 10 years to a few days/minutes, while the seismic moment can decrease by a factor of 6. Notably, the moment of aseismic slip (M0=109Nm) obtained during the nucleation phase modelled in our study is of the same order as the detection limit of local strain measurements using strain meters. These findings have significant implications for earthquake early warning systems, as the duration and moment of the nucleation phase will affect the likelihood of timely precursory signal detection. Interestingly, aseismic slip has been measured up to a few months before some recent large earthquakes, although in a different tectonic context than the model developed here, rekindling interest in the nucleation phase of earthquakes. In addition, our results have important implications for short and long term earthquake forecasting, as crustal fluid migration during the interseismic period may control fault strength and earthquake recurrence intervals. © 2019 The Author(s) Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165273
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth Sciences, Durham University, Durham, DH13LE, United Kingdom; Dipartimento di Scienze della Terra, Sapienza Università di Roma, Roma, 00185, Italy
Recommended Citation:
Snell T.,De Paola N.,van Hunen J.,et al. Modelling fluid flow in complex natural fault zones: Implications for natural and human-induced earthquake nucleation[J]. Earth and Planetary Science Letters,2020-01-01,530