DOI: 10.1016/j.epsl.2017.12.046
Scopus记录号: 2-s2.0-85044344317
论文题名: Implications of basal micro-earthquakes and tremor for ice stream mechanics: Stick-slip basal sliding and till erosion
作者: Barcheck C.G. ; Tulaczyk S. ; Schwartz S.Y. ; Walter J.I. ; Winberry J.P.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 486 起始页码: 54
结束页码: 60
语种: 英语
英文关键词: basal earthquake
; ice sheet basal conditions
; ice stream
; stick-slip sliding
; till
; West Antarctic Ice Sheet
Scopus关键词: Earthquakes
; Glacial geology
; Glaciers
; Slip forming
; Stick-slip
; Antarctic ice stream
; Basal conditions
; Frictional sliding
; Ice streams
; Micro-earthquakes
; Over consolidated
; till
; West antarctic ice sheets
; Ice
; erosion
; ice mechanics
; ice sheet
; ice stream
; microearthquake
; seismicity
; sliding
; stick-slip
; till
; Antarctic Ice Sheet
; Antarctica
; West Antarctic Ice Sheet
; West Antarctica
英文摘要: The Whillans Ice Plain (WIP) is unique among Antarctic ice streams because it moves by stick-slip. The conditions allowing stick-slip and its importance in controlling ice dynamics remain uncertain. Local basal seismicity previously observed during unstable slip is a clue to the mechanism of ice stream stick-slip and a window into current basal conditions, but the spatial extent and importance of this basal seismicity are unknown. We analyze data from a 2010–2011 ice-plain-wide seismic and GPS network to show that basal micro-seismicity correlates with large-scale patterns in ice stream slip behavior: Basal seismicity is common where the ice moves the least between unstable slip events, with small discrete basal micro-earthquakes happening within 10s of km of the central stick-slip nucleation area and emergent basal tremor occurring downstream of this area. Basal seismicity is largely absent in surrounding areas, where inter-slip creep rates are high. The large seismically active area suggests that a frictional sliding law that can accommodate stick-slip may be appropriate for ice stream beds on regional scales. Variability in seismic behavior over inter-station distances of 1–10 km indicates heterogeneity in local bed conditions and frictional complexity. WIP unstable slips may nucleate when stick-slip basal earthquake patches fail over a large area. We present a conceptual model in which basal seismicity results from slip-weakening frictional failure of over-consolidated till as it is eroded and mobilized into deforming till. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110026
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: Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA, United States; Oklahoma Geological Survey, University of Oklahoma, Norman, OK, United States; Institute for Geophysics, University of Texas at Austin, Austin, TX, United States; Department of Geological Sciences, Central Washington University, Ellensburg, WA, United States
Recommended Citation:
Barcheck C.G.,Tulaczyk S.,Schwartz S.Y.,et al. Implications of basal micro-earthquakes and tremor for ice stream mechanics: Stick-slip basal sliding and till erosion[J]. Earth and Planetary Science Letters,2018-01-01,486