Skip to main content

Imposed strain localization in the lower crust on seismic timescales

Abstract

We show using numerical model experiments that upper crustal faults can impose ductile localization in the mid and lower crust over the seismic cycle, with strain-rates and integrated creep strain enhanced by a factor of 10, or a factor of 100 if lower crust is also thermally weakened. Imposed ductile localization is caused by the transfer in stress from the lower tip of the frictional fault to the mid-crust. Within the weak ductile mid-lower crust, this stress transfer also promotes significantly enhanced creep rates in a lobe that extends down-dip from the lower end of the fault. Comparison of model results with the Alpine Fault of New Zealand, shows how the interaction of faulting with other localization mechanisms can account for key aspects of the geodetic strain accumulating across the Alpine Fault. Localization of ductile strain in the lower crust imposed by faulting in the upper crust could explain the extension of major faults into the lower crust observed in seismic imaging.

References

  1. Batt, G. and J. Braun, The tectonic evolution of the Southern Alps, New Zealand; insights from fully thermally coupled dynamical modelling, Geophys. J. Int., 136, 403–420, 1999.

    Article  Google Scholar 

  2. Beaumont, C., P. Fullsack, and J. Hamilton, Erosional control of active compressional orogens, in Thrust Tectonics, edited by K. R. McClay, pp. 1–18, Chapman and Hall, New York, 1992.

    Google Scholar 

  3. Beavan, J., and 10 others, Crustal deformation during 1994–1998 due to oblique continental collision in the central Southern Alps, New Zealand, and implications for seismic potential of the Alpine Fault, J. Geophys. Res., 104, 25233–25255, 1999.

    Article  Google Scholar 

  4. Beavan, J., and 6 others, A vertical deformation profile across the Southern Alps, New Zealand, from 3.5 years of continuous GPS data, Cahiers de Centre Européen de Géodynamique et Séismologie, Proceedings of the Workshop: The state of GPS vertical positioning precision: Separation of earth processes by space geodesy, edited by T. Van Dam, 24, 2004.

  5. Bouchon, M., The state of stress on some faults of the San Andreas as inferred from near-field strong motion data, J. Geophys. Res., 102, 11731–11744, 1997.

    Article  Google Scholar 

  6. Cattin, R. and J. Avouac, Modeling mountain building and the seismic cycle in the Himalaya of Nepal, J. Geophys. Res., 105, 13389–13407, 2000.

    Article  Google Scholar 

  7. Chéry, J., M. Zoback, and R. Hassani, An integrated mechanical model of the San Andreas fault in Central and Northern California, J. Geophys. Res., 106, 22051–22066, 2001.

    Article  Google Scholar 

  8. Davey, F., T. Henyey, S. Kleffmann, A. Melhuish, D. Okaya, T. Stern, and D. Woodward, Crustal reflections from the Alpine Fault zone, South Island, New Zealand, New Zealand J. Geol. Geophys., 38, 601–604, 1995.

    Article  Google Scholar 

  9. Ellis, S. and B. Stöckhert, Elevated stresses and creep rates beneath the brittle-ductile transition caused by faulting in the upper crust, J. Geophys. Res., 109, B05407, doi:10.1029/2003JB002744, 2004.

    Google Scholar 

  10. Gerbault, M., S. Henrys, and F. Davey, Numerical models of lithospheric deformation forming the Southern Alps of New Zealand, J. Geophys. Res., 108(B7), 2341, doi:10.1029/2001JB001716, 2003.

    Google Scholar 

  11. Hibbitt, Karlsson, and Sorensen, Abaqus/Standard User’s Manual, vol. 1 and 2, version 6.2, Hibbitt, Karlsson, and Sorensen Inc., Pawtucket, 2001.

    Google Scholar 

  12. Hobbs, B., A. Ord, and K. Regenauer-Lieb, Fluid reservoirs in the crust, seismic activity and mechanical coupling between the upper and lower crust, abstract, 2nd Intl Symposium on slip and flow processes in and below the seismogenic region, Tokyo, Mar 10-14, 2004.

    Google Scholar 

  13. Koons, P., R. Norris, D. Craw, and A. Cooper, Influence of exhumation on the structural evolution of transpressional plate boundaries: an example from the Southern Alps, New Zealand, Geology, 31, 3–6, 2003.

    Article  Google Scholar 

  14. Lachenbruch, A. and J. Sass, Heat flow and energetics of the San Andreas Fault zone, Journal of Geophysical Research, 85, 6185–6222, 1980.

    Article  Google Scholar 

  15. Little, T., R. Holcombe, and B. Ilg, Kinematics of oblique continental collision inferred from ductile microstructures and strain in mid-crustal Alpine schist, central South Island, New Zealand, Journal of Structural Geology, 24, 219–239, 2002.

    Article  Google Scholar 

  16. McGarr, A. and J. Fletcher, Mapping apparent stress and energy radiation over fault zones of major earthquakes, Bull. Seis. Soc. Am., 92, 1633–1646, 2002.

    Article  Google Scholar 

  17. Miller, S., Y. Ben-Zion, and J.-P. Burg, A three-dimensional fluid-controlled earthquake model: Behavior and implications, J. Geophys. Res., 104, 10621–10638, 1999.

    Article  Google Scholar 

  18. Montesi, L. and M. Zuber, A unified description of localization for application to large-scale tectonics, J. Geophys. Res., 107(B3), 10.1029/2001JB000465, 2002.

  19. Norris, R. and A. Cooper, Late Quaternary slip rates and slip partitioning on the Alpine Fault, New Zealand, J. Struc. Geol., 23, 507–520, 2001.

    Article  Google Scholar 

  20. Norris, R. and A. Cooper, Very high strain-rates recorded in mylonites along the Alpine Fault, New Zealand: Implications for the deep structure of plate boundary faults, J. Struc. Geol., 25, 2141–2157, 2003.

    Article  Google Scholar 

  21. Paterson, M. and F. Luan, Quartzite rheology under geological conditions, in Deformation Mechanisms, Rheology and Tectonics, edited by R. J. Knipe and E. H. Rutter, 54, Geol. Soc. Lond. Spec. Publ., pp. 299–307, 1990.

    Google Scholar 

  22. Regenauer-Lieb, K. and D. Yuen, Modeling shear zones in geological and planetary sciences: Solid- and fluid-thermal-mechanical approaches, Earth Sci. Rev., 63, 295–349, 2003.

    Article  Google Scholar 

  23. Starr, A., Slip in a crystal and rupture in a solid due to shear, Proc. Cambridge Philos. Soc., 24, 489–500, 1928.

    Article  Google Scholar 

  24. Stern, T., S. Kleffmann, D. Okaya, M. Scherwath, and S. Bannister, Low seismic-wave speeds and enhanced fluid pressure beneath the Southern Alps of New Zealand, Geology, 29, 679–692, 2001.

    Article  Google Scholar 

  25. Thatcher, W. and P. England, Ductile shear zones beneath strike-slip faults: Implications for the thermomechanics of the San Andreas fault zone, J. Geophys. Res., 103, 891–905, 1998.

    Article  Google Scholar 

  26. Walcott, R., Modes of oblique compression: Late Cenozoic tectonics of the South Island of New Zealand, Rev. Geophys., 36, 1–26, 1998.

    Article  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Susan Ellis.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Ellis, S., Stöckhert, B. Imposed strain localization in the lower crust on seismic timescales. Earth Planet Sp 56, 1103–1109 (2004). https://doi.org/10.1186/BF03353329

Download citation

Key words

  • Strain
  • localization
  • model
  • crust
  • rheology
  • fault
  • Alpine Fault
  • stress