Corrugated megathrust revealed offshore from Costa Rica

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Exhumed faults are rough, often exhibiting topographic corrugations oriented in the direction of slip; such features are fundamental to mechanical processes that drive earthquakes and fault evolution. However, our understanding of corrugation genesis remains limited due to a lack of in situ observations at depth, especially at subducting plate boundaries. Here we present three-dimensional seismic reflection data of the Costa Rica subduction zone that image a shallow megathrust fault characterized by corrugated, and chaotic and weakly corrugated topographies. The corrugated surfaces extend from near the trench to several kilometres down-dip, exhibit high reflection amplitudes (consistent with high fluid content/pressure) and trend 11–18° oblique to subduction, suggesting 15 to 25 mm yr1 of trench-parallel slip partitioning across the plate boundary. The corrugations form along portions of the megathrust with greater cumulative slip and may act as fluid conduits. In contrast, weakly corrugated areas occur adjacent to active plate bending faults where the megathrust has migrated up-section, forming a nascent fault surface. The variations in megathrust roughness imaged here suggest that abandonment and then reestablishment of the megathrust up-section transiently increases fault roughness. Analogous corrugations may exist along significant portions of subduction megathrusts globally.

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  1. 1.

    Aki, K. Asperities, barriers, characteristic earthquakes and strong motion prediction. J. Geophys. Res. 89, 5867–5872 (1984).

  2. 2.

    Scholz, C. H. The Mechanics of Earthquakes and Faulting (Cambridge Univ. Press, 2002).

  3. 3.

    Shi, Z. & Day, S. M. Rupture dynamics and ground motion from 3-D rough-fault simulations. J. Geophys. Res. 118, 1122–1141 (2013).

  4. 4.

    Dieterich, J. H. & Smith, D. E. Nonplanar faults: mechanics of slip and off-fault damage. Pure Appl. Geophys. 166, 1799–1815 (2009).

  5. 5.

    Petit, J. P. Criteria for the sense of movement on fault surfaces in brittle rocks. J. Struct. Geol. 9, 597–608 (1987).

  6. 6.

    Engelder, J. T. Microscopic wear grooves on slickensides: Indicators of paleoseismicity. J. Geophys. Res. 79, 4387–4392 (1974).

  7. 7.

    Candela, T. & Brodsky, E. E. The minimum scale of grooving on faults. Geology 44, 603–606 (2016).

  8. 8.

    Kirkpatrick, J. D. & Brodsky, E. E. Slickenline orientations as a record of fault rock rheology. Earth. Planet. Sci. Lett. 408, 24–34 (2014).

  9. 9.

    Wright, L. A., Otton, J. K. & Troxel, B.W. Turtleback surfaces of Death Valley viewed as phenomena of extensional tectonics. Geology 2, 53–54 (1974).

  10. 10.

    John, B. E. Geometry and evolution of a mid-crustal extensional fault system: Chemehuevi Mountains, southeastern California. Geol. Soc. Lond. Spec. Publ. 28, 313–335 (1987).

  11. 11.

    Clark, C. D. Mega-scale glacial lineations and cross-cutting ice-flow landforms. Earth Surf. Process. Landf. 18, 1–29 (1993).

  12. 12.

    Cann, J. R. et al. Corrugated slip surfaces formed at ridge-transform intersections on the Mid-Atlantic Ridge. Nature 385, 329–332 (1997).

  13. 13.

    King, E. C., Hindmarsh, R. C. A. & Stokes, C. R. Formation of mega-scale glacial lineations observed beneath a West Antarctic ice stream. Nat. Geosci. 2, 585–588 (2009).

  14. 14.

    Means, W. D. A newly recognized type of slickenside striation. J. Struct. Geol. 9, 585–590 (1987).

  15. 15.

    Clark, C. D., Tulacyzk, S., Stokes, C. R. & Canals, M. A groove-ploughing theory for the production of mega-scale glacial lineations, and implications for ice-stream mechanics. J. Glaciol. 49, 240–256 (2003).

  16. 16.

    Brodsky, E. E., Kirkpatrick, J. D. & Candela, T. Constraints from fault roughness on the scale-dependent strength of rocks. Geology 44, 1–4 (2016).

  17. 17.

    Lay, T., Ammon, C. J., Kanamori, H., Xue, L. & Kim, M. J. Possible large near-trench slip during the 2011 M w 9.0 off the Pacific coast of Tohoku Earthquake. Earth Planets Sp. Lett. 63, 687–692 (2011).

  18. 18.

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

  19. 19.

    Wang, K. & Bilek, S. L. Do subducting seamounts generate or stop large earthquakes? Geology 39, 819–822 (2011).

  20. 20.

    Chaves, E. J., Duboeuf, L., Schwartz, S. Y., Lay, T. & Kintner, J. Aftershocks of the 2012 M w 7.6 Nicoya, Costa Rica, earthquake and mechanics of the plate interface. Bull. Seismol. Soc. Am. 107, 1227–1239 (2017).

  21. 21.

    DeSchon, H. R. et al. Seismogenic zone structure of the southern Middle America Trench, Costa Rica. J. Geophys. Res. 108, 2491 (2003).

  22. 22.

    Kluesner, J. W. et al. High density of structurally controlled, shallow to deep water fluid seep indicators imaged offshore Costa Rica. Geochem. Geophys. Geosyst. 14, 519–539 (2013).

  23. 23.

    Bangs, N. L., McIntosh, K. D., Silver, E. A., Kluesner, J. W. & Ranero, C. R. Fluid accumulation along the Costa Rica subduction thrust and development of the seismogenic zone. J. Geophys. Res. 120, 67–86 (2014).

  24. 24.

    Kallweit, R. S. & Wood, L. C. The limits of resolution of zero-phase wavelets. Geophysics 47, 1035 (1982).

  25. 25.

    Chopra, S. & Marfurt, K. J. Preconditioning seismic data with 5D interpolation for computing geometric attributes. Lead. Edge 32, 1456–1459 (2013).

  26. 26.

    Tingdahl, K. M. & de Groot, P. Post-stack dip- and azimuth processing. J. Seism. Explor. 12, 113–126 (2003).

  27. 27.

    Marfurt, K. J. Robust estimates of 3D reflector dip and azimuth. Geophysics 71, P29–P40 (2006).

  28. 28.

    Roberts, A. Curvature attributes and their application to 3D interpreted horizons. First Break 19, 85–100 (2001).

  29. 29.

    Harris, R. N. et al. Frontal prism site U1412. In Proc. IODP Vol. 344 (eds Harris, R.N. et al.) 1–62 (IODP, 2013).

  30. 30.

    Tobin, H. J., Vannucchi, P. & Meschede, M. Structure, inferred mechanical properties, and implications for fluid transport in the decollement zone, Costa Rica convergent margin. Geology 29, 907–910 (2001).

  31. 31.

    Masson, D. G. Fault patterns at outer trench walls. Mar. Geophys. Res. 13, 209–225 (1991).

  32. 32.

    Tucholke, B. E., Lin, J. & Kleinrock, M. C. Megamullions and mullion structure defining oceanic metamorphic core complexes on the Mid-Atlantic Ridge. J. Geophys. Res. 103, 9857–9866 (1998).

  33. 33.

    Dinter, D. A. Late Cenozoic extension of the Alpine collisional orogen, northeastern Greece: origin of the north Aegean basin. Geol. Soc. Am. Bull. 110, 1208–1226 (1998).

  34. 34.

    Rafaelsen, B. et al. Geomorphology of buried glacigenic horizons in the Barents Sea from three-dimensional seismic data. Geol. Soc. Am. Spec. Publ. 203, 259–276 (2002).

  35. 35.

    Ghosh, A. et al. Rapid, continuous streaking of tremor in Cascadia. Geochem. Geophys. Geosyst. 11, 1–10 (2010).

  36. 36.

    Demets, C., Gordon, R. G., Argus, D. F. & Stein, S. Geologically current plate motions. Geophys. J. Int. 181, 1–80 (2010).

  37. 37.

    Kobayashi, D. et al. Kinematics of the western Caribbean: collision of the Cocos Ridge and upper plate deformation. Geochem. Geophys. Geosyst. 15, 1671–1683 (2014).

  38. 38.

    DeMets, C. A new estimate for present-day Cocos-Caribbean plate motion: implications for slip along the Central American volcanic arc. Geophys. Res. Lett. 28, 4043–4046 (2001).

  39. 39.

    LaFemina, P. et al. Fore-arc motion and Cocos Ridge collision in Central America. Geochem. Geophys. Geosyst. 10, Q05514 (2009).

  40. 40.

    Sagy, A., Brodsky, E. E. & Axen, G. J. Evolution of fault-surface roughness with slip. Geology 35, 283–286 (2007).

  41. 41.

    Adamek, S. & Tajima, F. Seismic rupture associated with subduction of the Cocos Ridge. Tectonics 6, 757–774 (1987).

  42. 42.

    Arroyo, I. G., Grevemeyer, I., Ranero, C. R. & von Huene, R. Interplate seismicity at the CRISP drilling site: The 2002 M w 6.4 Osa Earthquake at the southeastern end of the Middle America Trench. Geochem. Geophys. Geosyst. 15, 3035–3050 (2014).

  43. 43.

    Isacks, B. & Molnar, P. Mantle earthquake mechanisms and the sinking of the lithosphere. Nature 223, 1121–1124 (1969).

  44. 44.

    Rubin, A. M., Gillard, D. & Got, J. Streaks of microearthquakes along creeping faults. Nature 400, 635–641 (1999).

  45. 45.

    Ryan, W. B. F. et al. Global Multi-Resolution Topography synthesis. Geochem. Geophys. Geosyst. 10, Q03014 (2009).

  46. 46.

    Spagnolo, M. et al. Size, shape and spatial arrangement of mega-scale glacial lineations from a large and diverse dataset. Earth Surf. Process. Landf. 39, 1432–1448 (2014).

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This work was supported by US National Science Foundation grants OCE-0851380 and OCE-1154635. We thank dGB Earth Sciences for free access to OpendTect Pro and associated commercial plugins.

Author information


  1. Department of Earth and Planetary Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA

    • Joel H. Edwards
    • , Eli A. Silver
    • , Emily E. Brodsky
    • , Ruby Wood
    •  & Kristina Okamoto
  2. Pacific Coastal and Marine Science Center, US Geological Survey, Santa Cruz, CA, USA

    • Jared W. Kluesner
    •  & Daniel S. Brothers
  3. Institute for Geophysics, University of Texas at Austin, Austin, TX, USA

    • Nathan L. Bangs
  4. Earth and Planetary Sciences, McGill University, Montreal, Canada

    • James D. Kirkpatrick


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J.W.K., E.A.S. and N.L.B. obtained financial support for the marine seismic reflection program and collected and processed the seismic data. J.H.E. applied post processing, performed amplitude-driven tracking and extracted geometric attributes along the shallow megathrust. E.E.B. called attention to the corrugations. D.S.B. and J.D.K. furthered analysis of the corrugations. R.W. and K.O. extracted the scale of the corrugations. J.H.E. wrote the manuscript with contributions from all other authors.

Competing financial interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Joel H. Edwards.