DOI: 10.1016/j.epsl.2018.09.024
Scopus记录号: 2-s2.0-85054170173
论文题名: Localised thickening and grounding of an Antarctic ice shelf from tidal triggering and sizing of cryoseismicity
作者: Pirli M. ; Hainzl S. ; Schweitzer J. ; Köhler A. ; Dahm T.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 503 起始页码: 78
结束页码: 87
语种: 英语
英文关键词: East Antarctica
; event recurrence predictability
; ice-shelf grounding
; ice-shelf thickness
; stick-slip motion
; tidally modulated cryogenic seismicity
Scopus关键词: Earthquake effects
; Slip forming
; Stick-slip
; East antarctica
; event recurrence predictability
; Ice shelves
; Stick slip motion
; tidally modulated cryogenic seismicity
; Ice
英文摘要: We observe remarkably periodic patterns of seismicity rates and magnitudes at the Fimbul Ice Shelf, East Antarctica, correlating with the cycles of the ocean tide. Our analysis covers 19 years of continuous seismic recordings from Antarctic broadband stations. Seismicity commences abruptly during austral summer 2011 at a location near the ocean front in a shallow water region. Dozens of highly repetitive events occur in semi-diurnal cycles, with magnitudes and rates fluctuating steadily with the tide. In contrast to the common unpredictability of earthquake magnitudes, the event magnitudes show deterministic trends within single cycles and strong correlations with spring tides and tide height. The events occur quasi-periodically and the highly constrained event sources migrate landwards during rising tide. We show that a simple, mechanical model can explain most of the observations. Our model assumes stick-slip motion on a patch of grounded ice shelf, which is forced by the variations of the ocean-tide height and ice flow. The well fitted observations give new insights into the general process of frictional triggering of earthquakes, while providing independent evidence of variations in ice shelf thickness and grounding. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109612
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: Tårnbyveien 370, Skjetten2013, Norway; GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, 14473, Germany; NORSAR, Gunnar Randers vei 15, Kjeller, 2007, Norway; Centre for Earth Evolution and Dynamics (CEED), University of Oslo, P.O. Box 1028, Blindern, Oslo, 0315, Norway; Department of Geosciences, University of Oslo, P.O. Box 1047, Blindern, Oslo, 0316, Norway; Institute of Earth and Environmental Sciences, University of Potsdam, Potsdam, 14476, Germany
Recommended Citation:
Pirli M.,Hainzl S.,Schweitzer J.,et al. Localised thickening and grounding of an Antarctic ice shelf from tidal triggering and sizing of cryoseismicity[J]. Earth and Planetary Science Letters,2018-01-01,503