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Measuring the onset of locking in the Peru–Chile trench with GPS and acoustic measurements

Abstract

The subduction zone off the west coast of South America marks the convergence of the oceanic Nazca plate and the continental South America plate. Nazca–South America convergence over the past 23 million years has created the 6-km-deep Peru–Chile trench, 150 km offshore. High pressure between the plates creates a locked zone, leading to deformation of the overriding plate. The surface area of this locked zone is thought to control the magnitude of co-seismic release and is limited by pressure, temperature, sediment type and fluid content1. Here we present seafloor deformation data from the submerged South America plate obtained from a combination of Global Positioning System (GPS) receivers and acoustic transponders. We estimate that the measured horizontal surface motion perpendicular to the trench is consistent with a model having no slip along the thrust fault between 2 and 40 km depth. A tsunami in 1996, 200 km north of our site, was interpreted as being the result of an anomalously shallow interplate earthquake2. Seismic coupling at shallow depths, such as we observe, may explain why co-seismic events in the Peruvian subduction zone create large tsunamis.

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Figure 1: The GPS–acoustic approach to measure seafloor motion.
Figure 2: Bathymetric map of seafloor geodesy sites off the coast of Peru.
Figure 3: Models of surface deformation and plate organization.

References

  1. Tichelaar, B. W. & Ruff, L. J. Depth of seismic coupling along subduction zones. J. Geophys. Res. 98, 2017–2037 (1993)

    ADS  Article  Google Scholar 

  2. Satake, K. & Tanioka, Y. Sources of tsunami and tsunamigenic earthquakes in subduction zones. Pure Appl. Geophys. 154, 467–483 (1999)

    ADS  Article  Google Scholar 

  3. Cahill, T. & Isacks, I. Seismicity and shape of the subducted Nazca Plate. J. Geophys. Res. 97, 17503–17529 (1992)

    ADS  Article  Google Scholar 

  4. Gutscher, M. Andean subduction styles and their effect on thermal structure and interplate coupling. J. S. Am. Earth Sci. 15, 3–10 (2002)

    Article  Google Scholar 

  5. Moore, J. C. & Saffer, D. Updip limit of the seismogenic zone beneath the accretionary prism of southwest Japan: An effect of diagenetic to low-grade metamorphic processes and increasing effective stress. Geology 29, 183–186 (2001)

    ADS  CAS  Article  Google Scholar 

  6. Oleskevich, D. A., Hyndman, R. D. & Wang, K. The updip and downdip limits to great subduction earthquakes: Thermal and structural models of Cascadia, South Alaska, SW Japan, and Chile. J. Geophys. Res. 104, 14965–14991 (1999)

    ADS  Article  Google Scholar 

  7. Norabuena, E., Dixon, T. H., Stein, S. & Harrison, C. G. A. Decelerating Nazca–South America and Nazca–Pacific Plate motions. Geophys. Res. Lett. 26, 3405–3408 (1999)

    ADS  Article  Google Scholar 

  8. Norabuena, E. et al. Space geodetic observations of Nazca–South America convergence across the central Andes. Science 279, 358–362 (1998)

    ADS  CAS  Article  Google Scholar 

  9. Newman, A. V. et al. Along-strike variability in the seismogenic zone below Nicoya Peninsula, Costa Rica. Geophys. Res. Lett. 29, 38–41 (2002)

    Google Scholar 

  10. Chadwell, C. D. & Bock, Y. Direct estimation of absolute precipitable water in oceanic regions by GPS tracking of a coastal buoy. Geophys. Res. Lett. 28, 3701–3704 (2001)

    ADS  Article  Google Scholar 

  11. Spiess, F. N. et al. Precise GPS/acoustic positioning of seafloor reference points for tectonic studies. Physics Earth Planet. Inter. 108, 101–112 (1998)

    ADS  Article  Google Scholar 

  12. Webb, F. H. & Zumberge, J. F. An introduction to GIPSY/OASIS-II (JPL Publication D-11088, Jet Propulsion Lab., Pasadena, California, 1997)

    Google Scholar 

  13. Chadwell, C. D. Shipboard towers for Global Positioning System antennas. Ocean Eng. 30, 1467–1487 (2003)

    Article  Google Scholar 

  14. Gomberg, J. & Ellis, M. Topography and tectonics of the central New Madrid seismic zone: Results of numerical experiments using a three-dimensional boundary-element program. J. Geophys. Res. 99, 20299–20310 (1994)

    ADS  Article  Google Scholar 

  15. Krabbenhöft, A., Bialas, J., Kopp, H., Kukowski, N. & Hübscher, C. Crustal structure of the Peruvian continental margin from wide-angle seismic studies. Geophys. J. Int. 159, 749–764 (2004)

    ADS  Article  Google Scholar 

  16. Hampel, A., Kukowski, N., Bialas, J., Huebscher, C. & Heinbockel, R. Ridge subduction at an erosive margin: The collision of the Nazca Ridge in southern Peru. J. Geophys. Res. 109, B02101, doi:10.1029/2003JB002593 (2004)

    ADS  Article  Google Scholar 

  17. Sella, G., Dixon, T. & Mao, A. REVEL: A model for recent plate velocites from space geodesy. J. Geophys. Res. 107, 2081, doi:10.1029/2000JB00033 (2002)

    ADS  Article  Google Scholar 

  18. Angermann, D. & Klotz, J. R. Space geodetic estimation of the Nazca–South America Euler vector. Earth Planet. Sci. Lett. 171, 329–334 (1999)

    ADS  CAS  Article  Google Scholar 

  19. DeMets, C., Gordon, R., Argus, D. & Stein, S. Effect of recent revision to the geomagnetic reversal time scale on estimates of current plate motion. Geophys. Res. Lett. 21, 2191–2194 (1994)

    ADS  Article  Google Scholar 

  20. Larson, K. M., Freymueller, J. T. & Philipsen, S. Global plate velocities from the Global Positioning System. J. Geophys. Res. 102, 9961–9981 (1997)

    ADS  Article  Google Scholar 

  21. Wang, K. & Dixon, T. “Coupling” semantics and science in earthquake research. Eos 85, 180 (2004)

    ADS  Article  Google Scholar 

  22. Tichelaar, B. & Ruff, L. Seismic coupling along the Chilean subduction zone. J. Geophys. Res. 96, 11997–12022 (1991)

    ADS  Article  Google Scholar 

  23. Bevis, M., Smalley, R. Jr, Herring, T., Godoy, J. & Galban, F. Crustal motion north and south of the Arica Deflection: Comparing recent geodetic results from the Central Andes. Geochem. Geophys. Geosyst. 1, 1999GC000011 (1999)

  24. Schweller, W. J., Kulm, L. D. & Prince, R. A. in Nazca Plate: Crustal Formation and Andean Convergence (eds Kulm, L. D., Dymond, J., Dasch, E. J., Hussong, D. M. & Roderick, R.) 323–349 (Mem. Geol. Soc. Am. 154, Geological Society of America, Boulder, Colorado, 1981)

    Book  Google Scholar 

  25. Altimini, A., Sillard, P. & Boucher, C. ITRF2000: A new release of the International Terrestrial Reference Frame for earth science applications. J. Geophys. Res. 107, 2214, doi:10.1029.2001JB000561 (2002)

    ADS  Google Scholar 

  26. Smith, W. H. F. & Sandwell, D. T. Global seafloor topography from satellite altimetry and ship depth soundings. Science 277, 1957–1962 (1997)

    Google Scholar 

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Acknowledgements

We thank M. Bevis for comments and suggestions; R. Zimmerman, D. Rimington and D. Price for engineering support; and the Captain and crew of the R/V Roger Revelle. We thank the Instituto Geofisico Del Peru for operating the land GPS stations and the Instituto Del Mar Del Peru, Direccion de Higrografia y Navagacion, for support at sea. This work was supported by the Marine Geology and Geophysics Program of the US National Science Foundation.

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Correspondence to C. David Chadwell.

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Gagnon, K., Chadwell, C. & Norabuena, E. Measuring the onset of locking in the Peru–Chile trench with GPS and acoustic measurements. Nature 434, 205–208 (2005). https://doi.org/10.1038/nature03412

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