Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 28, 2013 | Supplemental Material + Published
Journal Article Open

Low friction along the high slip patch of the 2011 Mw 9.0 Tohoku-Oki earthquake required from the wedge structure and extensional splay faults

Abstract

We analyze the mechanical properties needed to account for the large shallow slip during the 2011 Tohoku-Oki earthquake and the activation of landward normal faulting within the forearc. We show that the morphology and internal structure of the forearc follows closely the prediction of the critical Coulomb wedge in horizontal compression, implying a high internal pore pressure ratio (λ = 0.7 + 0.14/ – 0.48) and a low effective basal friction (μ^(eff)_b = 0.14 + 0.18/ – 0.04). We then show that the activation of the normal fault requires a lower effective basal friction beneath the outer wedge than beneath the inner wedge (μ_outer ≤ 0.015), possibly due to transient dynamic weakening associated to the seismic rupture. Forearc normal faults could be considered as evidence for very efficient dynamic weakening along the megathrust and typify megathrust with high tsunamigenic potential.

Additional Information

© 2013 American Geophysical Union. Received 28 May 2013; revised 18 June 2013; accepted 18 June 2013; published 27 August 2013. This project was supported by the National Science Foundation through grant EAR-1118239 and by the Gordon and Betty Moore Foundation through grant GBMF 423.01 to the Caltech Tectonics Observatory. This is Tectonics Observatory contribution # 235. The Editor thanks two anonymous reviewers for their assistance in evaluating this paper.

Attached Files

Published - grl50682.pdf

Supplemental Material - README.rtf

Supplemental Material - text01.pdf

Supplemental Material - ts01.pdf

Files

ts01.pdf
Files (838.0 kB)
Name Size Download all
md5:ea568b0ee4b72892111b75923013a4fb
42.1 kB Preview Download
md5:2b2d86a820580ed4ba4597ec46fb79b8
598.9 kB Preview Download
md5:e8a78d899dfb8807b185e0c9c2ba88e5
2.8 kB Download
md5:cde46c710e90eb166e3fa0cf6e8c39ad
194.3 kB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 25, 2023