Skip to Main content Skip to Navigation
Journal articles

The postearthquake stress state on the Tohoku megathrust as constrained by reanalysis of the JFAST breakout data

Abstract : The Japan Trench Fast Drilling Project (JFAST) endeavored to establish the stress state on theshallow subduction megathrust that slipped during theM9 Tohoku earthquake. Borehole breakout datafrom the drill hole can constrain both the orientation and magnitude of the principal stresses. Here wereanalyze those data to refine our understanding of the stress state on the fault. In particular, we (1) improvethe identification of breakouts, (2) consider a fuller range of stress states consistent with the data, and (3)incorporate new and more robust laboratory constraints on rock strength. The original conclusion that theregion is in a normal faulting regime after the earthquake is strengthened by the new analysis. The combinedanalysis suggests that the earthquake released sufficient elastic strain energy to reset the local stressfield.
Document type :
Journal articles
Complete list of metadatas

https://hal.univ-lorraine.fr/hal-02982537
Contributor : Marianne Conin <>
Submitted on : Wednesday, October 28, 2020 - 4:27:24 PM
Last modification on : Wednesday, November 4, 2020 - 1:56:02 PM

Identifiers

Citation

Emily Brodsky, Demian Saffer, Patrick Fulton, Frederick Chester, Marianne Conin, et al.. The postearthquake stress state on the Tohoku megathrust as constrained by reanalysis of the JFAST breakout data. Geophysical Research Letters, American Geophysical Union, 2017, 44 (16), pp.8294-8302. ⟨10.1002/2017GL074027⟩. ⟨hal-02982537⟩

Share

Metrics

Record views

25