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Abrupt change in the dip of the subducting plate beneath north Chile

Nature Geoscience volume 5, pages 342–345 (2012)Cite this article

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Abstract

No large tsunamigenic earthquake has occurred in north Chile since 1877 and the region has been largely recognized as a mature seismic gap1,2,3,4,5,6,7,8,9. At the southern end of the seismic gap, the 2007 Mw 7.7 Tocopilla earthquake ruptured the deeper seismogenic interface, whereas the coupled upper interface remained unbroken4,6,7. Seismological studies onshore show a gently varying dip of 20° to 30° of the downgoing Nazca plate3,6, which extends from the trench down to depths of 40–50 km. Here, we study the lithospheric structure of the subduction zone of north Chile at about 22° S, using wide-angle seismic refraction and reflection data from land and sea, complemented by hypocentre data recorded during the 2007 Tocopilla aftershocks7. Our data document an abrupt increase in the dip of the subducting plate, from less than 10° to about 22°, at a depth of approximately 20 km. The distribution of the 2007 aftershocks indicates that the change in dip acted as a barrier for the propagation of the 2007 earthquake towards the trench, which, in turn, indicates that the subduction megathrust is not only segmented along the trench, but also in the direction of the dip. We propose that large-magnitude tsunamigenic earthquakes must cross the barrier and rupture the entire seismogenic zone.

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Figure 1: Seismotectonic setting of north Chile and seismic experiment.
Figure 2: Seismic velocity structure of the upper subduction zone of Tocopilla, north Chile and data example.
Figure 3: Summarized interpretation of the tomographic velocity–depth model.

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References

  1. Comte, D. & Pardo, M. Reappraisal of great historical eathquakes in northern Chile and southern Peru seismic gaps. Nat. Hazards 4, 23–44 (1991).

    Article  Google Scholar 

  2. Dorbath, L., Cisternas, A. & Dorbath, C. Quantitative assessment of great earthquakes in Peru. Bull. Seismol. Soc. Am. 80, 551–576 (1990).

    Google Scholar 

  3. Husen, S., Kissling, E. & Flueh, E. Local earthquake tomography of shallow subduction in north Chile: A combined onshore and offshore study. J. Geophys. Res. 105, 28183–28198 (2000).

    Article  Google Scholar 

  4. Béjar-Pizarro, M. et al. Asperities and barriers on the seismogenic zone in north Chile: State-of-the-art after the 2007 Mw 7.7 Tocopilla earthquake nferred by GPS and InSAR data. Geophys. J. Int. 183, 390–406 (2010).

    Article  Google Scholar 

  5. Klotz, J. et al. Earthquake cycle dominates contemporary crustal deformation in central and southern Andes. Earth Planet. Sci. Lett. 193, 437–446 (2001).

    Article  Google Scholar 

  6. Delouis, B., Pardo, M., Legrand, D. & Monfret, T. The Mw 7.7 Tocopilla earthquake of 14 November 2007 at the southern edge of the northern Chile seismic gap: Rupture in the deep part of the coupled plate interface. Bull. Seismol. Soc. Am. 99, 87–94 (2009).

    Article  Google Scholar 

  7. Peyrat, S. et al. Kinematic rupture process of the 2007 Tocopilla earthquake and its main aftershocks from teleseismic and strong-motion data. Geophys. J. Int. 182, 1411–1430 (2010).

    Article  Google Scholar 

  8. Malgrange, M. & Madariaga, R. Complex distribution of large thrust and normal fault earthquakes in the Chilean subduction zone. Geophys. J. R. Astron. Soc. 73, 489–505 (1983).

    Article  Google Scholar 

  9. Chlieh, et al. Interseismic coupling and seismic potential along the central Andes subduction zone. J. Geophys. Res. 116, B12405 (2011).

    Article  Google Scholar 

  10. Robinson, D. P., Das, S. & Watts, A. B. Earthquake rupture stalled by a subducting fracture zone. Science 312, 1203–1205 (2006).

    Article  Google Scholar 

  11. Scheuber, E., Bogdanic, T., Jensen, A. & Reutter, K-J. Tectonics of the Southern Central Andes 121–139 (Springer, 1994).

    Book  Google Scholar 

  12. Allmendinger, R. & Gonzalez, G. Neogene to Quaternary tectonics of the Coastal Cordillera, northern Chile. Tectonophysics 495, 93–110 (2010).

    Article  Google Scholar 

  13. Allmendinger, et al. Trench-parallel shortening in the northern Chilean forearc: Tectonic and climatic implications. GSA Bull. 117, 89–104 (2005).

    Article  Google Scholar 

  14. Hartley, A. J. et al. Development of a continental forearc: A Cenozoic example from the central Andes, northern Chile. Geology 28, 331–334 (2000).

    Article  Google Scholar 

  15. Armijo, R. & Thiele, R. Active faulting in northern Chile: Ramp stacking and lateral decoupling along a subduction plate boundary? Earth Planet. Sci. Lett. 98, 40–61 (1990).

    Article  Google Scholar 

  16. Mortimer, C. & Saric, N. Cenozoic studies in northernmost Chile. Geologishe Rundschau 64, 395–420 (1975).

    Article  Google Scholar 

  17. Paskoff, R. Sobre la Evolución Geomorfológica del Gran Acantilado Costero del Norte Grande de Chile PhD thesis, Univ. Católica de Chile (1979).

  18. Gonzalez, G., Cembrano, J., Carrizo, D., Macci, A. & Schneider, H. The link between forearc tectonics and Pliocene Quaternary deformation of the Coastal Cordillera, northern Chile. J. S. Am. Earth Sci. 16, 321–342 (2003).

    Article  Google Scholar 

  19. Patzwahl, R., Mechie, J., Schulze, A. & Giese, P. Two-dimensional velocity models of the Nazca plate subduction zone between 19.5° S and 25° S from wide-angle seismic measurements during the CINCA95 project. J. Geophys. Res. 104, 7293–7317 (1999).

    Article  Google Scholar 

  20. Sallares, V. & Ranero, C. R. Structure and tectonics of the erosional convergent margin off Antofagasta, north Chile (23° 30′S). J. Geophys. Res. 110, B06101 (2005).

    Article  Google Scholar 

  21. ANCORP Working Group Seismic reflection image revealing offset of Andean subduction-zone earthquake locations into oceanic mantle. Nature 397, 341–344 (1999).

  22. Von Huene, R. & Ranero, C. R. Subduction erosion and basal friction along the sediment-starved convergent margin off Antofagasta, Chile. J. Geophys. Res. 108, 2079 (2003).

    Article  Google Scholar 

  23. Ito, A. et al. Bending of the subducting oceanic plate and its implication for rupture propagation of large interplate earthquakes off Miyagi, Japan, in the Japan trench subduction zone. Geophys. Res. Lett. 32, L05310 (2005).

    Google Scholar 

  24. Fujie, G. et al. Confirming sharp bending of the Pacific plate in the northern Japan trench subduction zone by applying a traveltime mapping method. Phys. Earth Planet. Int. 157, 72–85 (2006).

    Article  Google Scholar 

  25. Von Huene, R., Weinrebe, W. & Heeren, F. Subduction erosion along the north Chile margin. J. Geodynam. 27, 345–358 (1999).

    Article  Google Scholar 

  26. Gonzalez, L., Dunai, G. T., Carrizo, D. & Allmendinger, R. Young displacements on the Atacama fault system, northern Chile from field observations and cosmogenic 21Ne concentrations. Tectonics 25, TC3006 (2006).

    Article  Google Scholar 

  27. Delouis, B., Philip, H., Dorbath, L. & Cisternas, A. Recent crustal deformation in the Antofagasta region (northern Chile) and the subduction process. Geophys. J. Int. 132, 302–338 (1998).

    Article  Google Scholar 

  28. Gonzalez, G. & Carrizo, D. Segmentación, cinemática y chronología relativa de la deformación tardía de la Falla Salar del Carmen, Sistema de Fallas Atacama, (23° 40′ S), norte de Chile. R. Geol. Chile 30, 223–244 (2003).

    Google Scholar 

  29. Marquardt, C., Lavenu, A., Ortliebc, L., Godoya, E. & Comte, D. Coastal neotectonics in southern central Andes: Uplift and deformation of marine terraces in northern Chile (27° S). Tectonophysics 394, 193–219 (2004).

    Article  Google Scholar 

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Acknowledgements

E.C-R. acknowledges the support of the Chilean National Science Foundation (FONDECYT) project 11090009. S.R and D.C acknowledge the support of FONDECYT project 1100429. We thank A. Fuenzalida, M. Lancieri and R. Madariaga for providing the hypocentre data. Marine data acquisition was financially supported by the German Ministry of Education, Science and Research. We also thank GeoForschungZentrum, Potsdam and the International Plate Boundary Observatory Chile for sharing the data.

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Authors and Affiliations

  1. Departamento de Geofísica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Blanco Encalada 2002, Santiago, Chile

    E. Contreras-Reyes, J. Jara, S. Ruiz & D. Carrizo

  2. Advanced Mining Technology Center, Universidad de Chile, Blanco Encalada 2002, Santiago, Chile

    J. Jara & D. Carrizo

  3. GEOMAR, Helmholtz Centre of Ocean Research, Wischhofstraße 1-3, D-24148 Kiel, Germany

    I. Grevemeyer

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  1. E. Contreras-Reyes
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  4. S. Ruiz
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  5. D. Carrizo
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Contributions

E.C-R., J.J. and I.G. analysed and processed the wide-angle seismic data. E.C-R., S.R., D.C. and I.G. interpreted and wrote the paper.

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Correspondence to E. Contreras-Reyes or S. Ruiz.

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Contreras-Reyes, E., Jara, J., Grevemeyer, I. et al. Abrupt change in the dip of the subducting plate beneath north Chile. Nature Geosci 5, 342–345 (2012). https://doi.org/10.1038/ngeo1447

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