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Postseismic deformation and the strength of ductile shear zones

Abstract

A good understanding of the rheology and strength of the whole crust is needed to obtain a physics-based earthquake prediction models. However, geodynamics-based and laboratory-based strength estimates disagree. Geodynamics tend to indicate that the actual strength of the plastic crust is less than deduced from laboratory experiments. Here, I evaluate lower crust strength from observations of transient postseismic deformation. Fault motion during an earthquake produces only a small stress perturbation, but that perturbation is sufficient to significantly affect the deformation rate of the aseismic levels of the crust, as observed by space geodesy. Even considering the non-linearity of plastic flow in geological materials, one cannot escape the conclusion that the pre-earthquake stress on the region where transient postseismic deformation occurs is not more than an order of magnitude larger than earthquake-induced stress perturbations. Using a simple shear zone model and assuming wet quartzite rheology, I show that such stress levels are not compatible with a km-scale shear zone, in spite of the geological evidence for localized deformation in the plastic crust. This implies that in plastic shear zones, rock strength is reduced. Possible explanations for the strength reduction include structural effects such as reduced grain size and/or a localized thermal anomaly associated with the shear zone.

References

  1. Ambraseys, N., The seismic activity of the Marmara sea region over the last 2000 years, Bull. Seism. Soc. Am., 92, 1–18, 2002.

    Article  Google Scholar 

  2. Brodie, K. H. and E. H. Rutter, Deformation mechanisms and rheology: Why marble is weaker than quartzite, J. Geol. Soc. London, 157, 1093–1096, 2000.

    Article  Google Scholar 

  3. Brace, W. F. and D. L. Kohlstedt, Limits on lithospheric stress imposed by laboratory measurements, J. Geophys. Res., 85, 6248–6252, 1980.

    Article  Google Scholar 

  4. Bürgmann, R., M. G. Kogan, V. E. Levin, C. H. Scholz, R. W. King, and G. M. Steblov, Rapid aseismic moment release following the 5 December, 1997 Kronotsky, Kamchatka, earthquake, Geophys. Res. Lett., 28, 1331–1334, 2001.

    Article  Google Scholar 

  5. Bürgmann, R., S. Ergintav, P. Segall, E. H. Hearn, S. McClusky, R. E. Reilinger, H. Woith, and J. Zschau, Time-dependent afterslip on and deep below the Izmit earthquake rupture, Bull. Seism. Soc. Am., 92, 126–137, 2002.

    Article  Google Scholar 

  6. Carter, N. L. and M. C. Tsenn, Flow properties of continental lithosphere, Tectonophysics, 136, 27–63, 1987.

    Article  Google Scholar 

  7. Cowie, P. A. and C. H. Scholz, Physical explanation for the displacement length relationship of faults using a post-yield fracture mechanics model, J. Struct. Geol., 14, 1133–1148, 1992.

    Article  Google Scholar 

  8. Evans, B. and D. L. Kohlstedt, Rheology of rocks, in Rock Physics and Phase Relations: A Handbook of Physical Constants, AGU Ref. Shelf3, edited by T. J. Ahrens, pp. 148–165, American Geophysical Union, Washington, 1995.

    Article  Google Scholar 

  9. Freed, A. M. and R. Bürgmann, Evidence of powerlaw flow in the Mojave Desert mantle, Nature, 430, 548–551, 2004.

    Article  Google Scholar 

  10. Freed, A. M. and J. Lin, Delayed triggering of the 1999 Hector Mine earthquake by viscoelastic stress transfer, Nature, 411, 180–183, 2001.

    Article  Google Scholar 

  11. Freymueller, J., R. Bürgmann, E. Calais, A. Freed, E. Price, and Denali Fault GPS Field Crew, An unparallel opportunity to study postseismic processes, EOS Trans. Am. Geophys. Union, 83, Fall Meet. Suppl., Abstract S72F-1365, 2002.

    Google Scholar 

  12. Hanks, T. C., Earthquake stress drops, ambient tectonic stresses, and stresses that drive plate motions, Pure Appl. Geophys., 115, 441–458, 1977.

    Article  Google Scholar 

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

    Article  Google Scholar 

  14. Hirth, G., C. Teyssier, and W. J. Dunlap, An evaluation of quartzite flow laws based on comparisons between experimentally and naturally deformed rocks, Int. J. Earth Sci., 90, 77–87, 2001.

    Article  Google Scholar 

  15. Hobbs, B. E., H.-B. Mühlhaus, and A. Ord, Instability, softening and localization of deformation, in Deformation Mechanisms, Rheology and Tectonics, Geol. Soc. Spec. Pub.54, edited by R. J. Knipe and E. H. Rutter, 15–34, pp. 143–165, The Geological Society of London, London, 1990.

    Google Scholar 

  16. Hsu, Y.-J., N. Bechor, P. Segall, S.-B. Yu, L.-C. Kuo, and K.-F. Ma, Rapid afterslip following the 1999 Chi-Chi, Taiwan earthquake, Geophys. Res. Lett., 29, 10.1029/2002GL014967, 2002.

  17. Hudnut, K. W., N. E. King, J. E. Galetzka, K. F. Stark, J. A. Behr, A. Aspiotes, S. van Wyk, R. Moffitt, S. Dockter, and F. Wyatt, Continuous GPS observations of postseismic deformation following the 16 October 1999 Hector Mine, California, Earthquake (Mw7.1), Bull. Seism. Soc. Am., 92, 1403–1422, 2002.

    Article  Google Scholar 

  18. Ida, Y., Cohesive forces across the tip of a longitudinal-shear crack and Griffith’s specific surface energy, J. Geophys. Res., 77, 3796–3805, 1972.

    Article  Google Scholar 

  19. Iio, Y. and Y. Kobayashi, Is the plastic flow uniformly distributed below the seismogenic region?, Tectonophysics, 364, 43–53, 2002.

    Article  Google Scholar 

  20. Iio, Y., Y. Kobayashi, and T. Tada, Large earthquakes initiate by the acceleration of slips on the downward extensions of seismogenic faults, Earth Planet. Sci. Lett., 202, 337–343, 2002.

    Article  Google Scholar 

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

    Google Scholar 

  22. Jónsson, S., P. Segall, R. Pedersen, and G. Björnsson, Post-earthquake ground movements correlated to pore-pressure transients, Nature, 424, 179–183, 2003.

    Article  Google Scholar 

  23. Kohlstedt, D. L., B. Evans, and S. J. Mackwell, Strength of the lithosphere: Constraints imposed by laboratory experiments, J. Geophys. Res., 100, 17587–17602, 1995.

    Article  Google Scholar 

  24. Küster, M. and B. Stöckhert, High differential stress and sublithostatic pore fluid pressure in the ductile regime-microstructural evidence for short-term post-seismic creep in the Sesia Zone, Western Alps, Tectonophysics, 303, 263–277, 1999.

    Article  Google Scholar 

  25. Luan, F. C. and M. S. Paterson, Preparation and deformation of synthetic aggregates of quartz, J. Geophys. Res., 97, 97301–97320, 1992.

    Google Scholar 

  26. Mai, P. M. and G. Beroza, Source scaling properties from finite-fault rupture models, Bull. Seism. Soc. Am., 90, 604–615, 2000.

    Article  Google Scholar 

  27. Marone, C. J., C. H. Scholz, and R. Bilham, On the mechanics of earthquake afterslip, J. Geophys. Res., 96, 8441–8452, 1991.

    Article  Google Scholar 

  28. McClusky, S., S. Balassanian, A. Barka, C. Demir, S. Ergintav, I. Georgiev, O. Gurkan, M. Hamburger, K. Hurst, H. Kahle, K. Kastens, G. Kekelidze, R. King, V. Kotzev, O. Lenk, S. Mahmoud, A. Mishin, M. Nadariya, A. Ouzonis, D. Paradissis, Y. Peter, M. Prilepin, R. Reilinger, I. Sanli, H. Seeger, A. Tealeb, M. N. Toksöz, and G. Veis, Global positioning constraints on plate kinematics and dynamics in the eastern Mediterranean and Caucasus, J. Geophys. Res., 105, 5695–5719, 2000.

    Article  Google Scholar 

  29. Melbourne, T. I., F. H. Webb, J. M. Stock, and C. Reigber, Rapid post-seismic transients in subduction zones from continuous GPS, J. Geophys. Res., 107, 2241, doi:10.1029/2001JB000555, 2002.

    Article  Google Scholar 

  30. Montési, L. G. J., Controls of shear zone rheology and tectonic loading on postseismic creep, J. Geophys. Res., 109, B10404, doi:10.1029/JB2003JB002925, 2004.

    Article  Google Scholar 

  31. Montési, L. G. J. and G. Hirth, Grain size evolution and the rheology of ductile shear zones: From laboratory experiments to postseismic creep, Earth Planet. Sci. Lett., 211, 97–110, 2003.

    Article  Google Scholar 

  32. Montési, L. G. J. and M. T. Zuber, A unified description of localization for application to large-scale tectonics, J. Geophys. Res., 107, doi:10.1029/2001JB000465, 2002.

  33. Okada, Y., Internal deformation due to shear and tensile faults in a half-space, Bull. Seism. Soc. Am., 82, 1018–1040, 1992.

    Google Scholar 

  34. Paterson, M. S., Problems in the extrapolation of laboratory data, Tectonophysics, 133, 33–43, 1987.

    Article  Google Scholar 

  35. Peltzer, G., P. Rosen, F. Rogez, and K. Hudnut, Poroelastic rebound in fault step-overs cause by pore fluid flow, Science, 273, 1202–1204, 1996.

    Article  Google Scholar 

  36. Peltzer, G., P. Rosen, F. Rogez, and K. Hudnut, Poro-elastic rebound along the Landers 1992 earthquake surface rupture, J. Geophys. Res., 103, 30131–30145, 1998.

    Article  Google Scholar 

  37. Ramsay, J. G., Shear zone geometry, a review, J. Struct. Geol., 2, 83–89, 1980.

    Article  Google Scholar 

  38. Regenauer-Lieb, K. and D. A. Yuen, Rapid conversion of elastic energy into shear heating during incipient necking of the lithosphere, Geophys. Res. Lett., 58, 2737–2740, 1998.

    Article  Google Scholar 

  39. Regenauer-Lieb, K. and D. A. 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 

  40. Renner, J. and B. Evans, Do calcite rocks obey the power-law creep equation?, in Deformation Mechanisms, Rheology and Tectonics: Current Status and Future Perspectives, Geol. Soc. Spec. Pub.200, edited by S. de Meer, M. R. Drury, J. H. P. de Bresser, and G. M. Pennock, pp. 293–307, The Geological Society of London, London, 2002.

    Google Scholar 

  41. Romanowicz, B., Strike-slip earthquakes on quasi-vertical transcurrent faults: Inferences for general scaling relations, J. Geophys. Res., 19, 481–484, 1992.

    Google Scholar 

  42. Savage, J. C., Equivalent strike-slip earthquake cycle in half-space and lithosphere-asthenosphere Earth models, J. Geophys. Res., 95, 4873–4879, 1990.

    Article  Google Scholar 

  43. Shaw, B. E. and C. H. Scholz, Slip-length scaling in large earthquakes: Observations and theory and implications for earthquake physics, Geophys. Res. Lett., 28, 2991–2994, 2001.

    Article  Google Scholar 

  44. Shibazaki, B., H. Tanaka, H. Horikawa, and Y. Iio, Modeling slip processes at the deeper part of the seismogenic zone using a constitutive law combining friction and flow laws, Earth Planets Space, 54, 1211–1218, 2002.

    Article  Google Scholar 

  45. Thatcher, W., Nonlinear strain buildup and the earthquake cycle on the San Andreas Fault, J. Geophys. Res., 88, 5893–5902, 1983.

    Article  Google Scholar 

  46. Tödheide, K., Water at high temperature and pressure, in Water: A Comprehensive Treatise, edited by F. Franks, pp. 463–514, 1972.

    Google Scholar 

  47. Trepmann, C. and B. Stöckhert, Quartz microstructures developed during non-steady state plastic flow at rapidly decaying stress and strain rate, J. Struct. Geol., 25, 2035–2051, 2003.

    Article  Google Scholar 

  48. Tse, S. T. and J. R. Rice, Crustal earthquake instability in relation to the depth variation of frictional slip properties, J. Geophys. Res., 91, 9452–9472, 1986.

    Article  Google Scholar 

  49. Vauchez, A. and A. Tommasi, Wrench faults down to the asthenosphere: Geological and geophysical evidence and thermo-mechanical effects, in Intraplate Strike-slip Deformation Belts, Geol. Soc. Spec. Pub.210, edited by F. Storti, R. E. Holdsworth, and F. Salvini, pp. 15–34, The Geological Society of London, London, 2003.

    Article  Google Scholar 

  50. Yagi, Y., M. Kikuchi, and T. Nishimura, Co-seismic slip, postseismic slip, and largest aftershock associated with the 1994 Sanriku-haruka-oki, Japan, earthquake, Geophys. Res. Lett., 30, 2177, doi:10.1029/2003GL018189, 2003.

    Article  Google Scholar 

  51. Yu, S.-B., Y.-J. Hsu, L.-C. Kuo, H.-Y Chen, and C.-C. Liu, GPS measurement of postseismic deformation following the 1999 Chi-Chi, Taiwan earthquake, J. Geophys. Res., 108, doi:10.1029/2003JB002396, 2003.

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Correspondence to Laurent G. J. Montési.

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Montési, L.G.J. Postseismic deformation and the strength of ductile shear zones. Earth Planet Sp 56, 1135–1142 (2004). https://doi.org/10.1186/BF03353332

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Key words

  • Shear zones
  • strength
  • postseismic deformation
  • rheology