Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

‘Melt welt’ mechanism of extreme weakening of gabbro at seismic slip rates

Abstract

Laboratory studies of frictional properties of rocks at slip velocities approaching the seismic range (0.1–1 m s−1), and at moderate normal stresses (1–10 MPa), have revealed a complex evolution of the dynamic shear strength, with at least two phases of weakening separated by strengthening at the onset of wholesale melting1,2,3,4. The second post-melting weakening phase is governed by viscous properties of the melt layer and is reasonably well understood5,6. The initial phase of extreme weakening, however, remains a subject of much debate. Here we show that the initial weakening of gabbro is associated with the formation of hotspots and macroscopic streaks of melt (‘melt welts’), which partially unload the rest of the slip interface. Melt welts begin to form when the average rate of frictional heating exceeds 0.1–0.4 MW m−2, while the average temperature of the shear zone is well below the solidus (250–450 °C). Similar heterogeneities in stress and temperature are likely to occur on natural fault surfaces during rapid slip, and to be important for earthquake rupture dynamics.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Experimentally measured evolution of the coefficient of friction at three different ‘near-critical’ velocities.
Figure 2: Power density versus time until the onset of weakening, for experiments at four different values of normal stress.
Figure 3: Observed critical slip velocity as a function of the estimated average temperature of the slip interface at the time of weakening.
Figure 4: Initiation of melt welts at the slip interface during the onset of dynamic weakening.
Figure 5: Evolution of shear stress and temperature through the onset of weakening.

References

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

    Article  ADS  Google Scholar 

  2. Goldsby, D. & Tullis, T. Low frictional strength of quartz rocks at subseismic slip rates. Geophys. Res. Lett. 29, (2002)

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

    Article  ADS  CAS  Google Scholar 

  4. Hirose, T. & Shimamoto, T. Fractal dimension of molten surfaces as a possible parameter to infer the slip-weakening distance of faults from natural pseudotachylytes. J. Struct. Geol. 25, 1569–1574 (2003)

    Article  ADS  Google Scholar 

  5. Fialko, Y. & Khazan, Y. Fusion by earthquake fault friction: Stick or slip? J. Geophys. Res. 110, B12407 (2005)

    Article  ADS  Google Scholar 

  6. Nielsen, S., Di Toro, G., Hirose, T. & Shimamoto, T. Frictional melt and seismic slip. J. Geophys. Res. 113, B01308 (2008)

    Article  ADS  Google Scholar 

  7. Rice, J. R. Heating and weakening of faults during earthquake slip. J. Geophys. Res. 111, B05311 (2006)

    Article  ADS  Google Scholar 

  8. Goldsby, D. & Tullis, T. Flash heating leads to low frictional strength of crustal rocks at earthquake slip rates. Science 334, 216–218 (2011)

    Article  ADS  CAS  Google Scholar 

  9. Reches, Z. & Lockner, D. A. Fault weakening and earthquake instability by powder lubrication. Nature 467, 452–455 (2010)

    Article  ADS  CAS  Google Scholar 

  10. Sammis, C., Lockner, D. & Reches, Z. The role of adsorbed water on the friction of a layer of submicron particles. Pure Appl. Geophys. 168, 2325–2334 (2011)

    Article  ADS  Google Scholar 

  11. Han, R., Shimamoto, T., Hirose, T., Ree, J.-H. & Ando, J. Ultralow friction of carbonate faults caused by thermal decomposition. Science 316, 878–881 (2007)

    Article  ADS  CAS  Google Scholar 

  12. Byerlee, J. Friction of rock. Pure Appl. Geophys. 116, 615–626 (1978)

    Article  ADS  Google Scholar 

  13. Di Toro, G. et al. Fault lubrication during earthquakes. Nature 471, 494–498 (2011)

    Article  ADS  CAS  Google Scholar 

  14. Chester, F. M. & Chester, J. S. Ultracataclasite structure and friction processes of the Punchbowl fault, San Andreas system, California. Tectonophysics 295, 199–221 (1998)

    Article  ADS  Google Scholar 

  15. Fialko, Y. Temperature fields generated by the elastodynamic propagation of shear cracks in the Earth. J. Geophys. Res. 109, B01303 (2004)

    ADS  Google Scholar 

  16. Dow, T. Thermoelastic effects in a thin sliding seal — a review. Wear 59, 31–52 (1980)

    Article  CAS  Google Scholar 

  17. Anderson, A. & Knapp, R. Hot spotting in automotive friction systems. Wear 135, 319–337 (1990)

    Article  Google Scholar 

  18. Lee, K. & Barber, J. Frictionally excited thermoelastic instability in automotive disk brakes. J. Tribol. 115, 607–614 (1993)

    Article  Google Scholar 

  19. Bowden, F. B. & Persson, P. A. Deformation heating and melting of solids in high speed friction. Proc. R. Soc. Lond. A 260, 433–458 (1960)

    ADS  MATH  Google Scholar 

  20. Molinari, A., Estrin, Y. & Mercier, S. Dependence of the coefficient of friction on the sliding conditions in the high velocity range. J. Tribol. 121, 35–41 (1999)

    Article  Google Scholar 

  21. Schedin, E. & Lehtinen, B. Galling mechanisms in lubricated systems: a study of sheet metal forming. Wear 170, 119–130 (1993)

    Article  CAS  Google Scholar 

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

    Article  ADS  Google Scholar 

  23. Lapusta, N., Rice, J. R., Ben-Zion, Y. & Zheng, G. Elastodynamic analysis for slow tectonic loading with spontaneous rupture episodes on faults with rate- and state- dependent friction. J. Geophys. Res. 105, 23765–23789 (2000)

    Article  ADS  Google Scholar 

  24. Abaqus/Simulia. v.6.11; available at http://www.3ds.com/products/simulia/overview/ (Dassault Systèmes, 2012)

Download references

Acknowledgements

We thank D. Lockner for comments that improved this manuscript. The SIO Marine Science Development Center provided the lathe used in our experiments. This work was supported by NSF (grant EAR-0838255).

Author information

Authors and Affiliations

Authors

Contributions

K.M.B. built the apparatus, K.M.B. and Y.F. designed and conducted experiments, Y.F. performed numerical modelling.

Corresponding authors

Correspondence to Kevin M. Brown or Yuri Fialko.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Figures 1-9 and Supplementary Tables 1-2. (PDF 3463 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Brown, K., Fialko, Y. ‘Melt welt’ mechanism of extreme weakening of gabbro at seismic slip rates. Nature 488, 638–641 (2012). https://doi.org/10.1038/nature11370

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature11370

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing