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Deep embrittlement and complete rupture of the lithosphere during the Mw 8.2 Tehuantepec earthquake


Subduction zones, where two tectonic plates converge, are generally dominated by large thrust earthquakes. Nonetheless, normal faulting from extensional stresses can occur as well. Rare large events of this kind in the instrumental record have typically nucleated in and ruptured the top half of old and cold lithosphere that is in a state of extension driven by flexure from plate bending. Such earthquakes are limited to regions of the subducting slab cooler than 650 °C and can be highly tsunamigenic, producing tsunamis similar in amplitude to those observed during large megathrust events. Here, we show from analyses of regional geophysical observations that normal faulting during the moment magnitude Mw 8.2 Tehuantepec earthquake ruptured the entire Cocos slab beneath the megathrust region. We find that the faulting reactivated a bend-fault fabric and ruptured to a depth well below the predicted brittle–ductile transition for the Cocos slab, including regions where temperature is expected to exceed 1,000 °C. Our findings suggest that young oceanic lithosphere is brittle to greater depths than previously assumed and that rupture is facilitated by wholesale deviatoric tension in the subducted slab, possibly due to fluid infiltration. We conclude that lithosphere can sustain brittle behaviour and fail in an earthquake at greater temperatures and ages than previously considered.

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Strong-motion data are available from the Strong Ground Motion Database System ( and by email request to Receiver Independent Exchange Format files with the raw GPS observations from the TLALOCNet archive are open and freely available at as well as at the UNAVCO archive University of Nevada, Reno static offset solutions are available at Tide gauge data are provided by Servicio Mareográfico Nacional from Universidad Nacional Autónoma de México and are available at and at DART buoy data can be obtained from

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  1. 1.

    Okal, E. A., Kirby, S. H. & Kalligeris, N. The Showa Sanriku earthquake of 1933 March 2: a global seismological reassessment. Geophys. J. Int. 206, 1492–1514 (2016).

  2. 2.

    Storchak, D. A. et al. Public release of the ISC–GEM Global Instrumental Earthquake Catalogue (1900–2009). Seism. Res. Lett. 84, 810–815 (2013).

  3. 3.

    Mori, N. et al. Nationwide post event survey and analysis of the 2011 Tohoku earthquake tsunami. Coastal Eng. J. 54, 1250001 (2012).

  4. 4.

    Craig, T. J., Copley, A. & Jackson, J. A reassessment of outer-rise seismicity and its implications for the mechanics of oceanic lithosphere. Geophys. J. Int. 197, 63–89 (2014).

  5. 5.

    Peacock, S. M. Are the lower planes of double seismic zones caused by serpentine dehydration in subducting oceanic mantle? Geology 29, 299–302 (2001).

  6. 6.

    Ranero, C. R., Morgan, J. P., McIntosh, K. & Reichert, C. Bending-related faulting and mantle serpentinization at the Middle America trench. Nature 425, 367–373 (2003).

  7. 7.

    Faccenda, M., Gerya, T. V. & Burlini, L. Deep slab hydration induced by bending-related variations in tectonic pressure. Nat. Geosci. 2, 790–793 (2009).

  8. 8.

    Naif, S., Key, K., Constable, S. & Evans, R. L. Water-rich bending faults at the Middle America trench. Geochem. Geophys. Geosyst. 16, 2582–2597 (2015).

  9. 9.

    Ranero, C. R., Villaseñor, A., Phipps Morgan, J. & Weinrebe, W. Relationship between bend‐faulting at trenches and intermediate‐depth seismicity. Geochem. Geophys. Geosyst. 6, Q12002 (2005).

  10. 10.

    Suárez, G. & Albini, P. Evidence for great tsunamigenic earthquakes (M 8.6) along the Mexican subduction zone. Bull. Seism. Soc. Am. 99, 892–896 (2009).

  11. 11.

    Herrmann, R. B. Computer programs in seismology: an evolving tool for instruction and research. Seism. Res. Lett. 84, 1081–1088 (2013).

  12. 12.

    Hernandez, B. et al. Rupture history of September 30, 1999 intraplate earthquake of Oaxaca, Mexico (M w = 7.5) from inversion of strong‐motion data. Geophys. Res. Lett. 28, 363–366 (2001).

  13. 13.

    M8.2—101km SSW of Tres Picos, M exico (United States Geological Survey, accessed 23 January 2018);

  14. 14.

    Hjörleifsdóttir, V., Singh, S. K. & Husker, A. Differences in epicentral location of Mexican earthquakes between local and global catalogs: an update. Geofís. Int. 55, 79–93 (2016).

  15. 15.

    Müller, R. D., Sdrolias, M., Gaina, C. & Roest, W. R. Age, spreading rates and spreading symmetry of the world’s ocean crust. Geochem. Geophys. Geosyst. 9, Q04006 (2008).

  16. 16.

    Manea, V. C. & Manea, M. in Volcanic Hazards in Central America Vol. 412 (eds Rose, W. I. et al.) 27–38 (GSA Special Papers, Geological Society of America, 2006).

  17. 17.

    Melgar, D. et al. Slip segmentation and slow rupture to the trench during the 2015, M w 8. 3 Illapel, Chile earthquake. Geophys. Res. Lett. 43, 961–966 (2016).

  18. 18.

    Ye, L., Lay, T., Bai, Y., Cheung, K. F. & Kanamori, H. The 2017 M w 8.2 Chiapas, Mexico, earthquake: energetic slab detachment. Geophys. Res. Lett. 44, 11824–11832 (2017).

  19. 19.

    Hillis, R. R. & Müller, R. D. in Evolution and Dynamics of the Australian Plate Vol. 372 (eds Hillis, R. R. & Müller, R. D.) 1–5 (GSA Special Papers, Geological Society of America, 2003).

  20. 20.

    Rogers, R. D., Kárason, H. & van der Hilst, R. D. Epeirogenic uplift above a detached slab in northern Central America. Geology 30, 1031–1034 (2002).

  21. 21.

    Franco, A. et al. Fault kinematics in northern Central America and coupling along the subduction interface of the Cocos Plate, from GPS data in Chiapas (Mexico), Guatemala and El Salvador. Geophys. J. Int. 189, 1223–1236 (2012).

  22. 22.

    Kelemen, P. B. & Hirth, G. A periodic shear-heating mechanism for intermediate-depth earthquakes in the mantle. Nature 446, 787–790 (2007).

  23. 23.

    Singh, S. K., Suárez, G. & Domínguez, T. The Oaxaca, Mexico, earthquake of 1931: lithospheric normal faulting in the subducted Cocos Plate. Nature 317, 56–58 (1985).

  24. 24.

    Ramírez-Herrera, M. T., Corona, N., Ruiz-Angulo, A., Melgar, D. & Zavala-Hidalgo, J. The 8 September 2017 tsunami triggered by the M w 8.2 intraplate earthquake, Chiapas, Mexico. Pure Appl. Geophys. 175, 25–34 (2018).

  25. 25.

    Kanamori, H. Seismological evidence for a lithospheric normal faulting—the Sanriku earthquake of 1933. Phys. Earth Planet. Int. 4, 289–300 (1971).

  26. 26.

    Melgar, D. & Bock, Y. Kinematic earthquake source inversion and tsunami runup prediction with regional geophysical data. J. Geophys. Res. Solid Earth 120, 3324–3349 (2015).

  27. 27.

    LeVeque, R. J., George, D. L. & Berger, M. J. Tsunami modelling with adaptively refined finite volume methods. Acta Numer. 20, 211–289 (2011).

  28. 28.

    Becker, J. J. et al. Global bathymetry and elevation data at 30 arc seconds resolution: SRTM30_PLUS. Mar. Geod. 32, 355–371 (2009).

  29. 29.

    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).

  30. 30.

    Bletery, Q. et al. Mega-earthquakes rupture flat megathrusts. Science 354, 1027–1031 (2016).

  31. 31.

    Wang, K., Wada, I. & Ishikawa, Y. Stresses in the subducting slab beneath southwest Japan and relation with plate geometry, tectonic forces, slab dehydration, and damaging earthquakes. J. Geophys. Res. 109, B08304 (2004).

  32. 32.

    Xu, X., Sandwell, D. T., Tymofyeyeva, E., González-Ortega, A. & Tong, X. Tectonic and anthropogenic deformation at the Cerro Prieto geothermal step-over revealed by Sentinel-1A InSAR. IEEE Trans. Geosci. Remote Sens. 55, 5284–5292 (2017).

  33. 33.

    Sandwell, D., Mellors, R., Tong, X., Wei, M. & Wessel, P. Open radar interferometry software for mapping surface deformation. Eos Trans. AGU 92, 234–234 (2011).

  34. 34.

    Wessel, P., Smith, W. H., Scharroo, R., Luis, J. & Wobbe, F. Generic Mapping Tools: improved version released. Eos Trans. AGU 94, 409–410 (2013).

  35. 35.

    Chen, C. W. & Zebker, H. A. Network approaches to two-dimensional phase unwrapping: intractability and two new algorithms. J. Opt. Soc. Am. A 17-3, 401–414 (2000).

  36. 36.

    Pasyanos, M. E., Masters, T. G., Laske, G. & Ma, Z. LITHO1.0: an updated crust and lithospheric model of the Earth. J. Geophys. Res. 119, 2153–2173 (2014).

  37. 37.

    Melgar, D. & Pérez-Campos, X. Imaging the Moho and subducted oceanic crust at the Isthmus of Tehuantepec, Mexico, from receiver functions. Pure Appl. Geophys. 168, 1449–1460 (2011).

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We thank D. Toomey, R. Burgmann and D. Sandwell for discussions. Strong-motion data used in this work were provided by Servicio Sismológico Nacional (SSN, Mexican National Seismological Service), and Unidad de Instrumentación Sismica (UIS) at the Instituto de Ingeniería (II), Universidad Nacional Autónoma de México (UNAM, National Autonomous University of Mexico). We thank their personnel for station maintenance, data acquisition and distribution. This material is partly based on data provided by the Transboundary, Land and Atmosphere Long-term Observational and Collaborative Network (TLALOCNet) operated by UNAVCO and the Servicio de Geodesia Satelital from Instituto de Geofísica-UNAM and supported by NSF grant EAR-1338091, CONACyT project 253760 and UNAM-PAPIIT projects IN104213 and IN109315-3. L. Salazar-Tlaczani at Servicio de Geodesia Satelital-UNAM provided invaluable support for the TLALOCNet field operations and stations maintenance. We are indebted to the staff and technicians of the Servicio Mareográfico Nacional who operate the tide gauge network. Some numerical computations were performed at the National Laboratory for Advanced Scientific Visualization at UNAM (LAVIS), and this work received support from LAVIS software engineers L. A. Aguilar Bautista, A. de León Cuevas and C. S. Flores Bautista. This research project was partially supported by the Japanese government through the programme Science and Technology Research Partnership for Sustainable Development (SATREPS) via the Japan International Cooperation Agency (JICA) and the Japan Science and Technology Agency (JST) with Grant Number 15543611. This work was also supported by a grant from the Romanian Ministry of National Education and Scientific Research, RDI Program for Space Technology and Advanced Research—STAR, project ID 513.

Author information

D.M. and A.R.-A. conceived and carried out the study. D.M. performed the slip inversion analysis. A.R.-A. analysed the sea-level data. E.S.G. performed the curvature and flexure calculations. M.M. and V.C.M. carried out the thermal modelling. D.M., A.R.-A., E.S.G., M.M. and V.C.M. created the figures and wrote the paper. X.X. carried out the InSAR analysis. M.T.R.-H., J.Z.-H. and N.C. provided and analysed the tsunami data. J.G. processed the high-rate GPS data. X.P.-C., E.C.-C. and L.R.-G. maintain and operate the seismic and geodetic networks. All authors discussed the results and revised the manuscript and figures.

Competing interests

The authors declare no competing interests.

Correspondence to Diego Melgar.

Supplementary information

  1. Supplementary Figures

    Supplementary Figures 1–10.

  2. Supplementary Dataset

    Multi-data slip inversion results.

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Further reading

Fig. 1: Regional tectonic context.
Fig. 2: Hypocentral biases between regional and teleseismic locations.
Fig. 3: Results of the kinematic slip inversion.
Fig. 4: Deep embrittlement during the rupture.