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Numerical modeling of long-term earthquake sequences on the NE Japan megathrust: Comparison with observations and implications for fault friction

Cubas, Nadaya and Lapusta, Nadia and Avouac, Jean-Philippe and Perfettini, Hugo (2015) Numerical modeling of long-term earthquake sequences on the NE Japan megathrust: Comparison with observations and implications for fault friction. Earth and Planetary Science Letters, 419 . pp. 187-198. ISSN 0012-821X. http://resolver.caltech.edu/CaltechAUTHORS:20150416-154546979

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Abstract

We use numerical modeling to investigate fault properties that explain key features of the 2011 Mw 9.0 Tohoku-Oki earthquake as well as the overall regional behavior of the NE Japan megathrust. In particular, we study the possibility that slip near the trench resulted from thermal pressurization on a shallow patch of the megathrust, and investigate whether low-velocity friction on that patch is rate-strengthening or rate-weakening. Our models also contain a deeper rate-weakening patch, not prone to efficient thermal pressurization, to account for the moderate-sized interplate seismicity. We produce earthquake sequences and aseismic slip in our models using 2D dynamic simulations that incorporate shear-induced temperature variations and the associated change in pore fluid pressure to capture thermal pressurization. We find that all our models can reproduce more frequent deeper moderate (Mw 7.5) events and less frequent larger events with substantial slip at shallow depth, as observed along the Fukushima–Miyagi segment of the Japan megathrust. However, only the scenario with a sufficiently rate-strengthening patch can match the thousand-year recurrence time of Tohoku-Oki-like earthquakes suggested by the historical and geological record, due to co-existence of seismic and aseismic slip at the shallow depths. This scenario also reproduces other characteristics of the Tohoku-Oki earthquake: the trenchward-skewed distribution of slip, the backward re-rupture of the deeper patch, as well as the weaker radiation at high frequency of the shallower portion of the rupture in spite of its larger slip.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1016/j.epsl.2015.03.002DOIArticle
http://www.sciencedirect.com/science/article/pii/S0012821X15001399PublisherArticle
ORCID:
AuthorORCID
Lapusta, Nadia0000-0001-6558-0323
Avouac, Jean-Philippe0000-0002-3060-8442
Additional Information:© 2015 Elsevier B.V. Received 20 November 2014; Received in revised form 28 February 2015; Accepted 3 March 2015; Available online 20 March 2015. We thanks Olivier Lengliné for helpfull discussion. We thank our two reviewers, Roland Bürgmann and Sylvain Barbot, for their constructive comments. This project was supported by the National Science Foundation through EAR grants 1118239 and 1142183 and by the Gordon and Betty Moore Foundation through grant GBMF #423.01 to the Caltech Tectonics Observatory. This is Tectonics Observatory contribution #280.
Group:Caltech Tectonics Observatory, Seismological Laboratory
Funders:
Funding AgencyGrant Number
NSFEAR 1118239
NSFEAR 1142183
Gordon and Betty Moore Foundation423.01
Subject Keywords:Tohoku-Oki earthquake; thermal pressurization; shallow propagation; 2D dynamic simulations of earthquake cycle
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Tectonics Observatory280
Record Number:CaltechAUTHORS:20150416-154546979
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20150416-154546979
Official Citation:Nadaya Cubas, Nadia Lapusta, Jean-Philippe Avouac, Hugo Perfettini, Numerical modeling of long-term earthquake sequences on the NE Japan megathrust: Comparison with observations and implications for fault friction, Earth and Planetary Science Letters, Volume 419, 1 June 2015, Pages 187-198, ISSN 0012-821X, http://dx.doi.org/10.1016/j.epsl.2015.03.002. (http://www.sciencedirect.com/science/article/pii/S0012821X15001399)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:56739
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:17 Apr 2015 03:01
Last Modified:01 Sep 2017 17:57

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