DOI: 10.1016/j.epsl.2017.12.021
Scopus记录号: 2-s2.0-85038209836
论文题名: Focal mechanisms and inter-event times of low-frequency earthquakes reveal quasi-continuous deformation and triggered slow slip on the deep Alpine Fault
作者: Baratin L.-M. ; Chamberlain C.J. ; Townend J. ; Savage M.K.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 484 起始页码: 111
结束页码: 123
语种: 英语
英文关键词: Alpine Fault
; focal mechanism
; low-frequency earthquake
; matched-filtering
; New Zealand
; slow deformation
Scopus关键词: Deformation
; Earthquakes
; Faulting
; Geophysics
; Matched filters
; Seismographs
; Seismology
; Signal to noise ratio
; Alpine Faults
; Focal mechanism
; Low-frequency earthquakes
; Matched filtering
; New zealand
; Slow deformation
; Fault slips
; deformation
; earthquake
; focal mechanism
; frequency analysis
; slip rate
; trigger mechanism
; Alpine Fault Zone
; New Zealand
; New Zealand
; South Island
英文摘要: Characterising the seismicity associated with slow deformation in the vicinity of the Alpine Fault may provide constraints on the stresses acting on a major transpressive margin prior to an anticipated great (≥M8) earthquake. Here, we use recently detected tremor and low-frequency earthquakes (LFEs) to examine how slow tectonic deformation is loading the Alpine Fault late in its typical ∼300-yr seismic cycle. We analyse a continuous seismic dataset recorded between 2009 and 2016 using a network of 10–13 short-period seismometers, the Southern Alps Microearthquake Borehole Array. Fourteen primary LFE templates are used in an iterative matched-filter and stacking routine, allowing the detection of similar signals corresponding to LFE families sharing common locations. This yields an 8-yr catalogue containing 10,000 LFEs that are combined for each of the 14 LFE families using phase-weighted stacking to produce signals with the highest possible signal-to-noise ratios. We show that LFEs occur almost continuously during the 8-yr study period and highlight two types of LFE distributions: (1) discrete behaviour with an inter-event time exceeding 2 min; (2) burst-like behaviour with an inter-event time below 2 min. We interpret the discrete events as small-scale frequent deformation on the deep extent of the Alpine Fault and LFE bursts (corresponding in most cases to known episodes of tremor or large regional earthquakes) as brief periods of increased slip activity indicative of slow slip. We compute improved non-linear earthquake locations using a 3-D velocity model. LFEs occur below the seismogenic zone at depths of 17–42 km, on or near the hypothesised deep extent of the Alpine Fault. The first estimates of LFE focal mechanisms associated with continental faulting, in conjunction with recurrence intervals, are consistent with quasi-continuous shear faulting on the deep extent of the Alpine Fault. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110081
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand
Recommended Citation:
Baratin L.-M.,Chamberlain C.J.,Townend J.,et al. Focal mechanisms and inter-event times of low-frequency earthquakes reveal quasi-continuous deformation and triggered slow slip on the deep Alpine Fault[J]. Earth and Planetary Science Letters,2018-01-01,484