A slump in the trench: Tracking the impact of the 2011 Tohoku-Oki earthquake

作者：Strasser M^*; Koelling M; Ferreira C dos Santos; Fink H G; Fujiwara T; Henkel S; Ikehara K; Kanamatsu T; Kawamura K; Kodaira S; Roemer M; Wefer G

来源：Geology, 2013, 41(8): 935-938.

DOI：10.1130/G34477.1

We present differential bathymetry and sediment core data from the Japan Trench, sampled after the 2011 Tohoku-Oki (offshore Japan) earthquake to document that prominent bathymetric and structural changes along the trench axis relate to a large (similar to 27.7 km(2)) slump in the trench. Transient geochemical signals in the slump deposit and analysis of diffusive re-equilibration of disturbed SO42- profiles over time constrain the triggering of the slump to the 2011 earthquake. We propose a causal link between earthquake slip to the trench and rotational slumping above a subducting horst structure. We conclude that the earthquake-triggered slump is a leading agent for accretion of trench sediments into the forearc and hypothesize that forward growth of the prism and seaward advance of the deformation front by more than 2 km can occur, episodically, during a single-event, large mega-thrust earthquake.

• 出版日期2013-8