Abstract
Quantification of stress accumulation and release during subduction zone seismic cycles requires an understanding of the distribution of fault slip during earthquakes. Reconstructions of slip are typically constrained to a single, known fault plane. Yet, slip has been shown to occur on multiple faults within the subducting plate1 owing to stress triggering2, resulting in phenomena such as earthquake doublets3. However, rapid stress triggering from the plate interface to faults in the overriding plate has not been documented. Here we analyse seismic data from the magnitude 7.1 Araucania earthquake that occurred in the Chilean subduction zone in 2011. We find that the earthquake, which was reported as a single event in global moment tensor solutions4,5, was instead composed of two ruptures on two separate faults. Within 12 s a thrust earthquake on the plate interface triggered a second large rupture on a normal fault 30 km away in the overriding plate. This configuration of partitioned rupture is consistent with normal-faulting mechanisms in the ensuing aftershock sequence. We conclude that plate interface rupture can trigger almost instantaneous slip in the overriding plate of a subduction zone. This shallow upper-plate rupture may be masked from teleseismic data, posing a challenge for real-time tsunami warning systems.
This is a preview of subscription content, access via your institution
Relevant articles
Open Access articles citing this article.
-
A recent deep earthquake doublet in light of long-term evolution of Nazca subduction
Scientific Reports Open Access 31 March 2017
-
An investigation into the remote triggering of the Oita earthquake by the 2016 Mw 7.0 Kumamoto earthquake using full wavefield simulation
Earth, Planets and Space Open Access 19 December 2016
-
A new classification of earthquake-induced landslide event sizes based on seismotectonic, topographic, climatic and geologic factors
Geoenvironmental Disasters Open Access 10 May 2016
Access options
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Rent or buy this article
Get just this article for as long as you need it
$39.95
Prices may be subject to local taxes which are calculated during checkout




References
Lay, T., Duputel, Z., Ye, L. & Kanamori, H. The December 7, 2012 Japan Trench intraplate doublet (Mw 7.2, 7.1) and interactions between near-trench intraplate thrust and normal faulting. Phys. Earth Planet. Inter. 220, 73–78 (2013).
Freed, A. M. Earthquake triggering by static, dynamic, and postseismic stress transfer. Annu. Rev. Earth Planet. Sci. 33, 335–367 (2004).
Ammon, C. J., Kanamori, H. & Lay, T. A great earthquake doublet and seismic stress transfer cycle in the central Kuril islands. Nature 451, 561–565 (2008).
National Earthquake Information Center M7.2–Araucania, Chile (United States Geological Survey, 2011); http://earthquake.usgs.gov/earthquakes/eventpage/usp000hsfq#scientific_tensor
Ekström, G., Nettles, M. & Dziewoński, A. M. The global CMT project 2004–2010: Centroid-moment tensors for 13,017 earthquakes. Phys. Earth Planet. Inter. 200–201, 1–9 (2012).
Moreno, M. et al. Toward understanding tectonic control on the Mw 8.8 2010 Maule Chile earthquake. Earth Planet. Sci. Lett. 321–322, 152–165 (2012).
Hayes, G. P., Wald, D. J. & Johnson, R. L. Slab1. 0: A three-dimensional model of global subduction zone geometries. J. Geophys. Res. 117, B01302 (2012).
Lay, T. et al. The 2009 Samoa–Tonga great earthquake triggered doublet. Nature 466, 964–968 (2010).
Audin, L., Lacan, P., Tavera, H. & Bondoux, F. Upper plate deformation and seismic barrier in front of Nazca subduction zone: The Chololo Fault System and active tectonics along the Coastal Cordillera, southern Peru. Tectonophysics 459, 174–185 (2008).
Melnick, D., Bookhagen, B., Strecker, M. R. & Echtler, H. P. Segmentation of megathrust rupture zones from fore-arc deformation patterns over hundreds to millions of years, Arauco peninsula, Chile. J. Geophys. Res. 114, B01407 (2009).
Rietbrock, A. et al. Aftershock seismicity of the 2010 Maule Mw = 8.8, Chile, earthquake: Correlation between co-seismic slip models and aftershock distribution? Geophys. Res. Lett. 39, L08310 (2012).
Moreno, M. S., Bolte, J., Klotz, J. & Melnick, D. Impact of megathrust geometry on inversion of coseismic slip from geodetic data: Application to the 1960 Chile earthquake. Geophys. Res. Lett. 36, L16310 (2009).
Sokos, E. & Zahradnik, J. A Matlab GUI for use with ISOLA Fortran codes. Users’ Guide (2006).
Zahradnik, J., Serpetsidaki, A., Sokos, E. & Tselentis, G.-A. Iterative deconvolution of regional waveforms and a double-event interpretation of the 2003 Lefkada Earthquake, Greece. Bull. Seismol. Soc. Am. 95, 159–172 (2005).
Hicks, S. P., Rietbrock, A., Ryder, I. M. A., Lee, C.-S. & Miller, M. Anatomy of a megathrust: The 2010 M8.8 Maule, Chile earthquake rupture zone imaged using seismic tomography. Earth Planet. Sci. Lett. 405, 142–155 (2014).
Haberland, C., Rietbrock, A., Lange, D., Bataille, K. & Dahm, T. Structure of the seismogenic zone of the southcentral Chilean margin revealed by local earthquake traveltime tomography. J. Geophys. Res. 114, B01317 (2009).
Zahradnik, J. & Sokos, E. The Mw 7.1 Van, Eastern Turkey, earthquake 2011: Two-point source modelling by iterative deconvolution and non-negative least squares. Geophys. J. Int. 196, 522–538 (2014).
Komatitsch, D., Erlebacher, G., Göddeke, D. & Michéa, D. High-order finite-element seismic wave propagation modeling with MPI on a large GPU cluster. J. Comput. Phys. 229, 7692–7714 (2010).
Hicks, S. P., Nippress, S. E. & Rietbrock, A. Sub-slab mantle anisotropy beneath south-central Chile. Earth Planet. Sci. Lett. 357, 203–213 (2012).
Hardebeck, J. L. Coseismic and postseismic stress rotations due to great subduction zone earthquakes. Geophys. Res. Lett. 39, L21313 (2012).
Blaser, L., Krüger, F., Ohrnberger, M. & Scherbaum, F. Scaling relations of earthquake source parameter estimates with special focus on subduction environment. Bull. Seismol. Soc. Am. 100, 2914–2926 (2010).
González, G. et al. Upper plate reverse fault reactivation and the unclamping of the megathrust during the 2014 northern Chile earthquake sequence. Geology 43, 671–674 (2015).
Singh, S. C. et al. Evidence of active backthrusting at the NE margin of Mentawai Islands, SW Sumatra. Geophys. J. Int. 180, 703–714 (2010).
Geersen, J., Völker, D., Behrmann, J. H., Reichert, C. & Krastel, S. Pleistocene giant slope failures offshore Arauco Peninsula, Southern Chile. J. Geol. Soc. Lond. 168, 1237–1248 (2011).
Frohlich, C. Triangle diagrams: Ternary graphs to display similarity and diversity of earthquake focal mechanisms. Phys. Earth Planet. Inter. 75, 193–198 (1992).
Hayes, G. P. et al. Seismotectonic framework of the 2010 February 27 Mw 8.8 Maule, Chile earthquake sequence. Geophys. J. Int. 195, 1034–1051 (2013).
Melnick, D. & Echtler, H. P. The Andes 565–568 (Springer, 2006).
Quintero, R., Zahradnik, J. & Sokos, E. Near-regional CMT and multiple-point source solution of the September 5, 2012, Nicoya, Costa Rica Mw 7.6 (GCMT) earthquake. J. South Am. Earth Sci. 55, 155–165 (2014).
Sokos, E. & Zahradnik, J. Evaluating centroid-moment-tensor uncertainty in the new version of ISOLA software. Seismol. Res. Lett. 84, 656–665 (2013).
Casarotti, E. et al. in Proceedings of the 16th International Meshing Roundtable 579–597 (Springer, 2008).
Acknowledgements
We are grateful to all field crews from partner organizations who participated in the deployment and servicing of seismic instruments used in this study. We thank J. Zahradník and E. Sokos for their assistance in setting up the ISOLA code. S.P.H. is financially supported by a NERC studentship (NE/J50015X/1).
Author information
Authors and Affiliations
Contributions
S.P.H. carried out the single and multiple point-source inversions, as well as the moment tensor inversion and aftershock relocations. S.P.H. wrote the manuscript, interpreted the results, and generated all figures. A.R. carried out the 3D full waveform simulations, wrote the manuscript, and interpreted the results.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Supplementary Information
Supplementary Information (PDF 2551 kb)
Rights and permissions
About this article
Cite this article
Hicks, S., Rietbrock, A. Seismic slip on an upper-plate normal fault during a large subduction megathrust rupture. Nature Geosci 8, 955–960 (2015). https://doi.org/10.1038/ngeo2585
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/ngeo2585
This article is cited by
-
Back-propagating supershear rupture in the 2016 Mw 7.1 Romanche transform fault earthquake
Nature Geoscience (2020)
-
A recent deep earthquake doublet in light of long-term evolution of Nazca subduction
Scientific Reports (2017)
-
A new classification of earthquake-induced landslide event sizes based on seismotectonic, topographic, climatic and geologic factors
Geoenvironmental Disasters (2016)
-
An investigation into the remote triggering of the Oita earthquake by the 2016 Mw 7.0 Kumamoto earthquake using full wavefield simulation
Earth, Planets and Space (2016)
-
Remote-controlled earthquakes
Nature Geoscience (2016)