Structure and Composition of the Plate-Boundary Slip Zone for the 2011 Tohoku-Oki Earthquake
The mechanics of great subduction earthquakes are influenced by the frictional properties, structure, andcomposition of the plate-boundary fault. We present observations of the structure and composition of theshallow source fault of the 2011 Tohoku-Oki earthquake and tsunami from boreholes drilled by the Integrated Ocean Drilling Program Expedition 343 and 343T. Logging-while-drilling and core-sample observations show a single major plate-boundary fault accommodated the large slip of the Tohoku-Oki earthquake rupture, as well as nearly all the cumulative interplate motion at the drill site. The localization of deformation onto a limited thickness (less than 5 meters) of pelagic clay is the defining characteristic of the shallow earthquake fault, suggesting that the pelagic clay may be a regionally important control on tsunamigenic earthquakes.
Journal or Conference Title
342, Number 6163
American Association for the Advancement of Science (AAAS)
Digital Object Identifier (DOI)
F. M. Chester et al., "Structure and composition of the plate-boundary slip zone for the 2011 Tohoku-Oki earthquake," Science, vol. 342, no. 6163, pp. 1208–1211, Dec. 2013.