Skip to main content

Advertisement

Stress on the seismogenic and deep creep plate interface during the earthquake cycle in subduction zones

Article metrics

Abstract

The deep creep plate interface extends from the down-dip edge of the seismogenic zone down to the base of the overlying lithosphere in subduction zones. Seismogenic/deep creep zone interaction during the earthquake cycle produces spatial and temporal variations in strains within the surrounding elastic material. Strain observations in the Nankai subduction zone show distinct deformation styles in the co-seismic, post-seismic, and inter-seismic phases associated with the 1946 great earthquake. The most widely used kinematic model to match geodetic observations has been a 2-D Savage-type model where a plate interface is placed in an elastic half-space and co-seismic slip occurs in the upper seismogenic portion of the interface, while inter-seismic deformation is modeled by a locked seismogenic zone and a constant slip velocity across the deep creep interface. Here, I use the simplest possible 2-D mechanical model with just two blocks to study the stress interaction between the seismogenic and deep creep zones. The seismogenic zone behaves as a stick-slip interface where co-seismic slip or stress drop constrain the model. A linear constitutive law for the deep creep zone connects the shear stress (σ) to the slip velocity across the plate interface (s′) with the material property of interface viscosity (ζ ) as: σ = ζ s′. The analytic solution for the steady-state two-block model produces simple formulas that connect some spatially-averaged geodetic observations to model quantities. Aside from the basic subduction zone geometry, the key observed parameter is τ, the characteristic time of the rapid post-seismic slip in the deep creep interface. Observations of τ range from about 5 years (Nankai and Alaska) to 15 years (Chile). The simple model uses these values for τ to produce estimates for ζ that range from 8.4 × 1013 Pa/m/s (in Nankai) to 6.5 × 1014 Pa/m/s (in Chile). Then, the model predicts that the shear stress acting on deep creep interface averaged over the earthquake cycle ranges from 0.1 MPa (Nankai) to 1.7 MPa (Chile). These absolute stress values for the deep creep zone are slightly smaller than the great earthquake stress drops. Since the great earthquake recurrence time ( T recur) is much larger than τ for Nankai, Alaska, and Chile, the model predicts that rapid post-seismic creep should re-load the seismogenic zone to about (1/3) of the co-seismic change; geodetically observed values range from about (1/10) to more than (1/2). Also, for the case of (Trecur/τ) 1, the model predicts that the slip velocity across the deep creep interface during the inter-seismic phase should be about (2/3) the plate tectonic velocity (R). Thus the deep creep velocity used in Savage-type models should be less than R. Even complex 3-D models with non-linear creep laws should make a similar prediction for inter-seismic deep creep rates. At present, it seems that geodetic observations at Nankai and other subduction zones are more consistent with a deep creep rate of R rather than (2/3) R. This discrepancy is quite puzzling and is difficult to explain in the context of a 2-D steady-state earthquake cycle model. Future observational and modeling studies should examine this apparent discrepancy to gain more understanding of the earthquake cycle in subduction zones.

References

  1. Ando, M., Source mechanism and tectonic significance of historical earthquakes along the Nankai Trough, Japan, Tectonophysics, 27, 119–140, 1975.

  2. Ando, M., A fault model of the 1946 Nankaido earthquake derived from tsunami data, Phys. Earth Planet. Int., 28, 320–336, 1982.

  3. Barrientos, S. E., G. Plafker, and E. Lorca, Postseismic coastal uplift in southern Chile, Geophys. Res. Lett., 19, 701–704, 1992.

  4. Brown, L. D., R. Reilinger, S. Holdahl, and E. Balazs, Postseismic crustal uplift near Anchorage, Alaska, J. Geophys. Res., 82, 3369–3378, 1977.

  5. Cifuentes, I. and P. Silver, Low-frequency source characteristics of the great 1960 Chilean earthquake, J. Geophys. Res., 94, 643–664, 1989.

  6. Dieterich, J., Constitutive properties of faults with simulated gouge, in Mechanical Behavior of Crustal Rocks, AGU Geophys. Mono. 24, pp. 103–120, American Geophysical Union, Washington, D.C., 1981.

  7. Dixon, T. H., GPS measurement of relative motion of the Cocos and Caribbean plates and strain accumulation across the middle America trench, Geophys. Res. Lett., 20, 2167–2170, 1993.

  8. Dmowska, R., G. Zheng, and J. Rice, Seismicity and deformation at convergent margins due to heterogeneous coupling, J. Geophys. Res., 101, 3015–3030, 1996.

  9. Heki, K., S. Miyazaki, and H. Tsuji, Silent fault slip following an interplate thrust earthquake at the Japan trench, Nature, 386, 595–598, 1997.

  10. Hirahara, K., FEM modeling for seismic cycle of great interplate earthquakes following the rate- and state-dependent friction law—preliminary analysis, in Recurrence of great interplate earthquakes and its mechanism (Kochi Workshop proceedings), pp. 181–186, Sci. & Tech. Agency, Kochi, 1999.

  11. Hyndman, R., K. Wang, and M. Yamano, Thermal constraints on the seismogenic portion of the southwestern Japan subduction thrust, J. Geophys. Res., 100, 15,373–15,392, 1995.

  12. Ito, T., S. Yoshioka, and S. Miyazaki, Interplate coupling in southwest Japan deduced from inversion analysis of GPS data, Phys. Earth Planet. Int., 1999 (submitted).

  13. Kanamori, H. and D. L. Anderson, Theoretical basis of some empirical relations in seismology, Bull. Seism. Soc. Am., 65, 1073–1095, 1975.

  14. Kanamori, H. and J. Cipar, Focal process of the great Chilean earthquake May 22, 1960, Phys. Earth Planet. Int., 9, 128–136, 1974.

  15. Kasahara, K., Aseismic faulting following the 1973 Nemuro-Oki earthquake, Hokkaido, Japan (a possibility), Pageoph, 113, 127–139, 1975.

  16. Mogi, K., Temporal variation of crustal deformation during the days preceding a thrust-type great earthquake—the 1944 Tonankai earthquake of magnitude 81, Pageoph, 122, 765–780, 1985.

  17. Nomanbhoy, N. and L. J. Ruff, A simple discrete elements model of large multiplet earthquakes, J. Geophys. Res., 101, 5707–5724, 1996.

  18. Peacock, S. M., Thermal and petrologic structure of subduction zones, in Subduction: Top to Bottom, edited by G. Bebout, D. Scholl, S. Kirby, and J. Platt, pp. 119–133, AGU Geophys. Mono. 96, American Geophys Union, Washington, D.C., 1996.

  19. Plafker, G., Alaskan earthquake of 1964 and Chilean earthquake of 1960, implications for arc tectonics, J. Geophys. Res., 77, 901–925, 1972.

  20. Plafker, G. and J. C. Savage, Mechanism of the Chilean earthquakes of May 21 and May 22, 1960, Geol. Soc. Am. Bull., 81, 1001–1030, 1970.

  21. Rice, J. R. and S. T. Tse, Dynamic motion of a single degree of freedom system following a rate and state dependent friction law, J. Geophys. Res., 91, 521–530, 1986.

  22. Ruff, L. J., Asperity distributions and large earthquake occurrence in subduction zones, Tectonophys., 211, 1–23, 1992.

  23. Ruff, L. J., Dynamic stress drop of recent earthquakes: variations within subduction zones, Pageoph, 154, 409–431, 1999.

  24. Sagiya, T., Spatio-temporal variation of interplate coupling along the Nankai Trough deduced from geodetic data inversion, in Recurrence of great interplate earthquakes and its mechanism (Kochi Workshop proceedings), pp. 148–152, Sci. & Tech. Agency, Kochi, 1999.

  25. Sagiya, T. and W. Thatcher, Coseismic slip resolution along a plate boundary megathrust: the Nankai trough, southwest Japan, J. Geophys. Res., 104, 1111–1129, 1999.

  26. Sato, T. and M. Matsu’ura, Cyclic crustal movement, steady uplift of marine terraces, and evolution of the island arc-trench system in southwest Japan, Geophys. J. Int., 111, 617–629, 1992.

  27. Savage, J. C., Interseismic uplift at the Nankai subduction zone, southwest Japan, 1951–1990, J. Geophys. Res., 100, 6339–6350, 1995.

  28. Savage, J. C. and W. Thatcher, Interseismic deformation at the Nankai Trough, Japan, subduction zone, J. Geophys. Res., 97, 11,117–11,135, 1992.

  29. Savage, J. C., J. Svarc, W. Prescott, and W. Gross, Deformation across the rupture zone of the 1964 Alaska earthquake, 1993–1997, J. Geophys. Res., 103, 21,275–21,283, 1998.

  30. Scholz, C. H., The Mechanics of Earthquakes and Faulting, 439 pp., Cambridge Univ. Press, Cambridge, 1990.

  31. Seno, T., S. Stein, and A. Gripp, A model for the motion of the Philippine Sea plate consistent with NUVEL-1 and geological data, J. Geophys. Res., 98, 17,941–17,948, 1993.

  32. Stuart, W. D., Forecast model for great earthquakes at the Nankai Trough subduction zone, Pageoph, 126, 619–642, 1988.

  33. Stuart, W. and T. Sagiya, Initial results from a three-dimensional fault model for earthquake cycles at the Nankai subduction zone, in Recurrence of great interplate earthquakes and its mechanism (Kochi Workshop proceedings), pp. 173–180, Sci. & Tech. Agency, Kochi, 1999.

  34. Tabei, T, Lateral heterogeneity of subduction process at the Nankai Trough inferred from GPS data, in Recurrence of great interplate earthquakes and its mechanism (Kochi Workshop proceedings), pp. 6–12, Sci. & Tech. Agency, Kochi, 1999.

  35. Tanioka, Y. and K. Satake, Coseismic slip distribution of the 1946 Nankai earthquake and aseismic slips caused by the earthquake, Earth Planets Space, 53, this issue, 235–241, 2001.

  36. Thatcher, W. and J. Rundle, A visco-elastic coupling model for cyclic deformation due to periodically repeated earthquakes at subduction zones, J. Geophys. Res., 89, 7631–7640, 1984.

  37. Tichelaar, B. W. and L. J. Ruff, Depth of seismic coupling along subduction zones, J. Geophys. Res., 98, 2017–2037, 1993.

  38. Wang, K. and J. He, Mechanics of low-stress forearcs: Nankai and Cascadia, J. Geophys. Res., 104, 15,191–15,205, 1999.

  39. Yabuki, T. and M. Matsu’ura, Geodetic data inversion using a Bayesian information criterion for spatial distribution of fault slip, Geophys. J. Int., 109, 363–375, 1992.

  40. Yoshioka, S., Three-dimensional numerical simulation of displacement and strain fields associated with the 1944 Tonankai and 1946 Nankai earthquakes, in Recurrence of great interplate earthquakes and its mechanism (Kochi Workshop proceedings), pp. 203–209, Sci. & Tech. Agency, Kochi, 1999.

Download references

Author information

Correspondence to Larry J. Ruff.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Ruff, L.J. Stress on the seismogenic and deep creep plate interface during the earthquake cycle in subduction zones. Earth Planet Sp 53, 307–320 (2001) doi:10.1186/BF03352387

Download citation

Keywords

  • Subduction Zone
  • Stress Drop
  • Seismogenic Zone
  • Plate Interface
  • Coseismic Slip