Journal: |
Science 2019 No.12
clicks:303 |
Title:
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Author:
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Fei Zhang1,2, Zhangdong Jin1,2,3,*, A. Joshua West4, Zhisheng An1,2, Robert G. Hilton5, Jin Wang1,5, Gen Li4, Alexander L. Densmore5, Jimin Yu6,7, Xiaoke Qiang1,2,8, Youbin Sun1,2, Liangbo Li1,9, Long |
Adress: |
SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China. |
Abstract:
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Infrequent extreme events such as large earthquakes pose hazards and have lasting impacts on landscapes and biogeochemical cycles. Sediments provide valuable records of past events, but unambiguously identifying event deposits is challenging because of nonlinear sediment transport processes and poor age control. Here, we have been able to directly track the propagation of a tectonic signal into stratigraphy using reservoir sediments from before and after the 2008 Wenchuan earthquake. Cycles in magnetic susceptibility allow us to define a precise annual chronology and identify the timing and nature of the earthquake’s sedimentary record. The grain size and Rb/Sr ratio of the sediments responded immediately to the earthquake. However, the changes were muted until 2 years after the event, when intense monsoonal runoff drove accumulation of coarser grains and lower Rb/Sr sediments. The delayed response provides insight into how climatic and tectonic agents interact to control sediment transfer and depositional processes.
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Comment: |
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