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Friction falls towards zero in quartz rock as slip velocity approaches seismic rates


An important unsolved problem in earthquake mechanics is to determine the resistance to slip on faults in the Earth's crust during earthquakes1. Knowledge of coseismic slip resistance is critical for understanding the magnitude of shear-stress reduction and hence the near-fault acceleration that can occur during earthquakes, which affects the amount of damage that earthquakes are capable of causing. In particular, a long-unresolved problem is the apparently low strength of major faults2,3,4,5,6, which may be caused by low coseismic frictional resistance3. The frictional properties of rocks at slip velocities up to 3 mm s-1 and for slip displacements characteristic of large earthquakes have been recently simulated under laboratory conditions7. Here we report data on quartz rocks that indicate an extraordinary progressive decrease in frictional resistance with increasing slip velocity above 1 mm s-1. This reduction extrapolates to zero friction at seismic slip rates of 1 m s-1, and appears to be due to the formation of a thin layer of silica gel on the fault surface: it may explain the low strength of major faults during earthquakes.

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Figure 1: Typical experimental sequence and results.
Figure 2: Dependence of friction on slip displacement for samples slid at 3, 30 and 100 mm s-1.
Figure 3: Dependence of steady-state friction on slip velocity.


  1. Kanamori, H. Mechanics of earthquakes. Annu. Rev. Earth Planet. Sci. 22, 207–237 (1994)

    ADS  Article  Google Scholar 

  2. Brune, J. N., Henyey, T. L. & Roy, R. F. Heat flow, stress, and rate of slip along the San Andreas fault, California. J. Geophys. Res. 74, 3821–3827 (1969)

    ADS  Article  Google Scholar 

  3. Lachenbruch, A. H. Frictional heating, fluid pressure, and the resistance to fault motion. J. Geophys. Res. 85, 6249–6272 (1980)

    Google Scholar 

  4. Mount, V. S. & Suppe, J. State of stress near the San Andreas fault: Implications for wrench tectonics. Geology 15, 1143–1146 (1987)

    ADS  Article  Google Scholar 

  5. Zoback, M. D. et al. New evidence on the state of stress of the San Andreas fault system. Science 238, 1105–1111 (1987)

    ADS  CAS  Article  Google Scholar 

  6. Rice, J. R. in Fault Mechanics and Transport Properties of Rocks (eds Evans, B. & Wong, T.) 475–503 (Academic, San Diego, 1992)

    Google Scholar 

  7. Goldsby, D. & Tullis, T. E. Low frictional strength of quartz rocks at subseismic slip rates. Geophys. Res. Lett. 29, doi:10.1029/2002GL015240 (2002)

  8. Dieterich, J. H. Time-dependent friction and the mechanics of stick slip. Pure Appl. Geophys. 116, 790–806 (1978)

    ADS  Article  Google Scholar 

  9. Byerlee, J. D. Friction of rocks. Pure Appl. Geophys. 116, 615–626 (1978)

    ADS  Article  Google Scholar 

  10. Tullis, T. E. & Weeks, J. D. Constitutive behavior and stability of frictional sliding of granite. Pure Appl. Geophys. 124, 383–414 (1986)

    ADS  Article  Google Scholar 

  11. Tsutsumi, A. & Shimamoto, T. High-velocity frictional properties of gabbro. Geophys. Res. Lett. 24, 699–702 (1997)

    ADS  Article  Google Scholar 

  12. Spray, J. G. Artificial generation of pseudotachylite using friction welding apparatus: simulation of melting on a fault plane. J. Struct. Geol. 9, 49–60 (1987)

    ADS  Article  Google Scholar 

  13. Mair, K. & Marone, C. Shear heating in granular layers. Pure Appl. Geophys. 157, 1847–1866 (2000)

    ADS  Article  Google Scholar 

  14. Hickman, S. H. Stress in the lithosphere and the strength of active faults. Rev. Geophys. 29, 759–775 (1991)

    ADS  Google Scholar 

  15. McKenzie, D. P. & Brune, J. N. Melting of fault planes during large earthquakes. Geophys. J. R. Astron. Soc. 29, 65–78 (1972)

    ADS  Article  Google Scholar 

  16. Spray, J. G. Viscosity determinations of some frictionally generated silicate melts — implications for fault zone rheology at high-strain rates. J. Geophys. Res. 98, 8053–8068 (1993)

    ADS  Article  Google Scholar 

  17. Brune, J. N., Brown, S. & Johnson, P. A. Rupture mechanism and interface separation in foam rubber models of earthquakes: a possible solution to the heat flow paradox and the paradox of large overthrusts. Tectonophysics 218, 59–67 (1993)

    ADS  Article  Google Scholar 

  18. Melosh, H. J. Dynamic weakening of faults by acoustic fluidization. Nature 397, 601–606 (1996)

    ADS  Article  Google Scholar 

  19. Brodsky, E. E. & Kanamori, H. Elastohydrodynamic lubrication of faults. J. Geophys. Res. 106, 16357–16374 (2001)

    ADS  Article  Google Scholar 

  20. Knauth, L. P. in Silica: Physical Behavior, Geochemistry, and Materials Applications (eds Heaney, P. J., Prewitt, C. T. & Gibbs, G. V.) 233–258 (Mineralogical Society of America, Washington DC, 1994)

    Book  Google Scholar 

  21. Yund, R. A., Blanpied, M. L., Tullis, T. E. & Weeks, J. D. Amorphous material in high strain experimental fault gouges. J. Geophys. Res. 95, 15589–15602 (1990)

    ADS  Article  Google Scholar 

  22. Archard, J. F. The temperature of rubbing surfaces. Wear 2, 438–455 (1958)

    Article  Google Scholar 

  23. Dieterich, J. H. & Kilgore, B. D. Imaging surface contacts: power law contact distributions and contact stresses in quartz, calcite, glass, and acrylic plastic. Tectonophysics 256, 219–239 (1996)

    ADS  Article  Google Scholar 

  24. Deer, W. A., Howie, R. A. & Zussman, J. An Introduction to the Rock Forming Minerals 2nd edn (Longman Scientific and Technical, Harlow, UK, 1992)

    Google Scholar 

  25. Titone, B., Sayre, K., Di Toro, G., Goldsby, D. L. & Tullis, T. E. The role of water in the extraordinary frictional weakening of quartz rocks during rapid sustained slip. Eos 82, T31B–0841 (2001)

    Google Scholar 

  26. Ferguson, J. & Kemblowski, Z. Applied Fluid Rheology (Elsevier, New York, 1991)

    Google Scholar 

  27. Power, W. L. & Tullis, T. E. The relationship between slickenside surfaces in fine-grained quartz and the seismic cycle. J. Struct. Geol. 11, 879–893 (1989)

    ADS  Article  Google Scholar 

  28. Killick, A. M. & Roering, C. An estimate of the physical conditions of pseudotachylite formation in the West Rand Goldfield, Witwatersrand Basin, RSA. Tectonophysics 284, 247–259 (1998)

    ADS  Article  Google Scholar 

  29. Perrin, G. O., Rice, J. R. & Zheng, G. Self-healing slip pulse on a frictional surface. J. Mech. Phys. Solids 43, 1461–1495 (1994)

    ADS  MathSciNet  Article  Google Scholar 

  30. Beeler, N. M. & Tullis, T. E. Self-healing slip pulses in dynamic rupture models due to velocity dependent strength. Bull. Seismol. Soc. Am. 86, 1130–1148 (1996)

    Google Scholar 

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We thank C. Bull for assistance with the experimental apparatus, D. McGuirl for fabrication of experimental parts, M. Parmentier for assistance with the FEM program, K. Mair for suggestions about Fig. 1, J. Rice and N. Beeler for discussions throughout the course of this study, and J. Tullis and C. Marone for comments on the manuscript. This research was supported by the US Geological Survey, the US National Science Foundation, and MURST (Italy).

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Correspondence to Terry E. Tullis.

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Di Toro, G., Goldsby, D. & Tullis, T. Friction falls towards zero in quartz rock as slip velocity approaches seismic rates. Nature 427, 436–439 (2004).

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