Title

Structure and Composition of the Plate-Boundary Slip Zone for the 2011 Tohoku-Oki Earthquake

Abstract

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.

Publication Date

12-2013

Journal or Conference Title

Science

Volume

342, Number 6163

Pages

1208–1211

Publisher

American Association for the Advancement of Science (AAAS)

Digital Object Identifier (DOI)

10.1126/science.1243719

Document Type

Journal Article