DOI: 10.1016/j.quascirev.2015.04.001
Scopus记录号: 2-s2.0-84930204824
论文题名: Turbidite paleoseismology along the active continental margin of Chile - Feasible or not?
作者: Bernhardt A. ; Melnick D. ; Hebbeln D. ; Lückge A. ; Strecker M.R.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 120 起始页码: 71
结束页码: 92
语种: 英语
英文关键词: Chile convergent margin
; Earthquake
; Seismoturbidites
; Turbidite paleoseismology
Scopus关键词: Deposition
; Ocean currents
; Sediment transport
; Sediments
; Seismology
; Site selection
; Submarine geology
; Turbidity
; Convergent margin
; Geomorphic conditions
; Paleoseismology
; Planktonic foraminifera
; Recurrence intervals
; Sedimentation rates
; Seismoturbidites
; Subduction earthquakes
; Earthquakes
; continental margin
; depocenter
; earthquake magnitude
; earthquake recurrence
; Holocene
; marine sediment
; paleoseismicity
; planktonic foraminifera
; Pleistocene
; radiocarbon dating
; recurrence interval
; seismotectonics
; turbidite
; turbidity current
; Chile
; Foraminifera
英文摘要: Much progress has been made in estimating recurrence intervals of great and giant subduction earthquakes using terrestrial, lacustrine, and marine paleoseismic archives. Recent detailed records suggest these earthquakes may have variable recurrence periods and magnitudes forming supercycles. Understanding seismic supercycles requires long paleoseismic archives that record timing and magnitude of such events. Turbidite paleoseismic archives may potentially extend past earthquake records to the Pleistocene and can thus complement commonly shorter-term terrestrial archives. However, in order to unambiguously establish recurring seismicity as a trigger mechanism for turbidity currents, synchronous deposition of turbidites in widely spaced, isolated depocenters has to be ascertained. Furthermore, characteristics that predispose a seismically active continental margin to turbidite paleoseismology and the correct sample site selection have to be taken into account.Here we analyze 8 marine sediment cores along 950km of the Chile margin to test for the feasibility of compiling detailed and continuous paleoseismic records based on turbidites. Our results suggest that the deposition of areally widespread, synchronous turbidites triggered by seismicity is largely controlled by sediment supply and, hence, the climatic and geomorphic conditions of the adjacent subaerial setting. The feasibility of compiling a turbidite paleoseismic record depends on the delicate balance between sufficient sediment supply providing material to fail frequently during seismic shaking and sufficiently low sedimentation rates to allow for coeval accumulation of planktonic foraminifera for high-resolution radiocarbon dating.We conclude that offshore northern central Chile (29-32.5°S) Holocene turbidite paleoseismology is not feasible, because sediment supply from the semi-arid mainland is low and almost no Holocene turbidity-current deposits are found in the cores. In contrast, in the humid region between 36 and 38°S frequent Holocene turbidite deposition may generally correspond to paleoseismic events. However, high terrigenous sedimentation rates prevent high-resolution radiocarbon dating. The climatic transition region between 32.5 and 36°S appears to be best suited for turbidite paleoseismology. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59914
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth and Environmental Sciences, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, Potsdam, Germany; MARUM - Center for Marine Environmental Sciences, University of Bremen, Leobener Straße, Bremen, Germany; Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Stilleweg 2, Hannover, Germany
Recommended Citation:
Bernhardt A.,Melnick D.,Hebbeln D.,et al. Turbidite paleoseismology along the active continental margin of Chile - Feasible or not?[J]. Quaternary Science Reviews,2015-01-01,120