Skip to main content

Thank you for visiting 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.

Resonant slow fault slip in subduction zones forced by climatic load stress


Global Positioning System (GPS) measurements at subduction plate boundaries often record fault movements similar to earthquakes but much slower, occurring over timescales of 1 week to 1 year. These ‘slow slip events’ have been observed in Japan1,2, Cascadia3,4,5,6,7, Mexico8,9, Alaska10 and New Zealand11. The phenomenon is poorly understood, but several observations hint at the processes underlying slow slip. Although slip itself is silent, seismic instruments often record coincident low-amplitude tremor in a narrow (1–5 cycles per second) frequency range12. Also, modelling of GPS data3,7,9 and estimates of tremor location13 indicate that slip focuses near the transition from unstable (‘stick-slip’) to stable friction at the deep limit of the earthquake-producing seismogenic zone. Perhaps most intriguingly, slow slip is periodic at several locations, with recurrence varying from 6 to 18 months depending on which subduction zone (or even segment) is examined4,5,6,9. Here I show that such periodic slow fault slip may be a resonant response to climate-driven stress perturbations. Fault slip resonance helps to explain why slip events are periodic, why periods differ from place to place, and why slip focuses near the base of the seismogenic zone. Resonant slip should initiate within the rupture zone of future great earthquakes, suggesting that slow slip may illuminate fault properties that control earthquake slip.

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.


All prices are NET prices.

Figure 1: GPS time series and slow slip models from Guerrero, Mexico.
Figure 2: Stress on the fault surface.
Figure 3: Relationships of rate- and state-dependent frictional parameters to resonant slow slip.


  1. Hirose, H., Hirahara, K., Kimata, F., Fujii, N. & Miyazaki, S. A slow thrust slip event following the two 1996 Hyuganada earthquakes beneath the Bungo Channel, southwest Japan. Geophys. Res. Lett. 26, 3237–3240 (1999)

    ADS  Article  Google Scholar 

  2. Obara, K., Hirose, H., Yamamizu, F. & Kasahara, K. Episodic slow slip events accompanied by non-volcanic tremors in southwest Japan subduction zone. Geophys. Res. Lett. 31, doi:10.1029/2004GL020848 (2004)

  3. Dragert, H., Wang, K. & James, T. S. A silent slip event on the deeper Cascadia subduction interface. Science 292, 1525–1528 (2001)

    ADS  CAS  Article  Google Scholar 

  4. Miller, M. M., Melbourne, T., Johnson, D. J. & Sumner, W. Q. Periodic slow earthquakes from the Cascadia subduction zone. Science 295, 2423 (2002)

    CAS  Article  Google Scholar 

  5. Szeliga, W., Melbourne, T. I., Miller, M. M. & Santillan, V. M. Southern Cascadia episodic slow earthquakes. Geophys. Res. Lett. 31, doi:10.1029/2004GL020824 (2004)

  6. Malone, S., Rogers, G., Dragert, H., McCausland, W. & Johnson, D. Review of episodic tremor and slip in Cascadia. Eos 85, abstr. S53A (2004)

  7. Dragert, H., Wang, K. & Rogers, G. Geodetic and seismic signatures of episodic tremor and slip in the northern Cascadia subduction zone. Earth Planets Space 56, 1143–1150 (2004)

    ADS  Article  Google Scholar 

  8. Lowry, A. R., Larson, K. M., Kostoglodov, V. & Bilham, R. G. Transient slip on the subduction interface in Guerrero, southern Mexico. Geophys. Res. Lett. 28, 3753–3756 (2001)

    ADS  Article  Google Scholar 

  9. Lowry, A. R., Larson, K. M., Kostoglodov, V. & Sanchez, O. The fault slip budget in Guerrero, southern Mexico. Geophys. J. Int. (submitted)

  10. Cohen, S. C. & Freymueller, J. T. Crustal deformation in the southcentral Alaska subduction zone. Adv. Geophys. 47, 1–63 (2004)

    ADS  Article  Google Scholar 

  11. Douglas, A., Beavan, J., Wallace, L. & Townend, J. Slow slip on the northern Hikurangi subduction interface, New Zealand. Geophys. Res. Lett. 32, doi:10.1029/2005GL023607 (2005)

  12. Rogers, G. & Dragert, H. Episodic tremor and slip on the Cascadia subduction zone: The chatter of silent slip. Science 300, 1942–1943 (2003)

    ADS  CAS  Article  Google Scholar 

  13. Kao, H. et al. A wide depth distribution of seismic tremors along the northern Cascadia margin. Nature 436, 841–844 (2005)

    ADS  CAS  Article  Google Scholar 

  14. Chouet, B. Resonance of a fluid-driven crack: Radiation properties and implications for the source of long-period events and harmonic tremor. J. Geophys. Res. 93, 4375–4400 (1988)

    ADS  Article  Google Scholar 

  15. Melbourne, T. I. & Webb, F. H. Slow but not quite silent. Science 300, 1886–1887 (2003)

    CAS  Article  Google Scholar 

  16. Flück, P., Hyndman, R. D. & Wang, K. Three-dimensional dislocation model for great earthquakes of the Cascadia subduction zone. J. Geophys. Res. 102, 20539–20550 (1997)

    ADS  Article  Google Scholar 

  17. Shibazaki, B. & Iio, Y. On the physical mechanism of silent slip events along the deeper part of the seismogenic zone. Geophys. Res. Lett. 30, doi:10.1029/2003GL017047 (2003)

  18. Liu, Y. & Rice, J. R. Aseismic slip transients emerge spontaneously in three-dimensional rate and state modeling of subduction earthquake sequences. J. Geophys. Res. 110, doi:10.1029/2004JB003424 (2005)

  19. Shen, Z. K., Wang, Q., Bürgmann, R. & Wan, Y. Pole-tide modulation of slow slip events at circum-Pacific subduction zones. Bull. Seismol. Soc. Am. 95, 2009–2015 (2005)

    Article  Google Scholar 

  20. Wahr, J. M. in Geodesy and Global Geodynamics (eds Moritz, H. & Sunkel, H.) 327–380 (Technical Univ. of Graz, Austria, 1983)

    Google Scholar 

  21. Dziewonski, A. M. & Anderson, D. L. Preliminary reference Earth model. Phys. Earth Planet. Inter 25, 297–356 (1981)

    ADS  Article  Google Scholar 

  22. Fan, Y. & van den Dool, H. Climate Prediction Center global monthly soil moisture data set at 0.5 degrees resolution for 1948 to present. J. Geophys. Res. 109, doi:10.1029/2004JD004345 (2004)

  23. Wahr, J. M., Molenaar, M. & Bryan, F. Time variability of the Earth's gravity field: Hydrological and oceanic effects and their possible detection using GRACE. J. Geophys. Res. 103, 30205–30230 (1998)

    ADS  Article  Google Scholar 

  24. Anderson, J. G. et al. Strong ground motion from the Michoacan, Mexico, earthquake. Science 233, 1043–1049 (1986)

    ADS  CAS  Article  Google Scholar 

  25. Perfettini, H., Schmittbuhl, J., Rice, J. R. & Cocco, M. Frictional response induced by time-dependent fluctuations of the normal loading. J. Geophys. Res. 106, 13455–13472 (2001)

    ADS  Article  Google Scholar 

  26. Perfettini, H. & Schmittbuhl, J. Periodic loading on a creeping fault: Implications for tides. Geophys. Res. Lett. 28, 435–438 (2001)

    ADS  Article  Google Scholar 

  27. Dieterich, J. H. Modeling of rock friction 1. Experimental results and constitutive equations. J. Geophys. Res. 84, 2161–2168 (1979)

    ADS  Article  Google Scholar 

  28. Blanpied, M. L., Lockner, D. A. & Byerlee, J. D. Frictional slip of granite at hydrothermal conditions. J. Geophys. Res. 100, 13045–13064 (1995)

    ADS  CAS  Article  Google Scholar 

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

    Google Scholar 

  30. Williams, C. A. & McCaffrey, R. Stress rates in the central Cascadia subduction zone inferred from an elastic plate model. Geophys. Res. Lett. 28, 2125–2128 (2001)

    ADS  Article  Google Scholar 

Download references


I thank K. Larson for analysis of GPS data used in this paper; V. Kostoglodov, O. Sanchez and J. A. Santiago for contributions to instrumentation and data collection in Mexico; and J. Wahr and R. Bilham for discussions about the topic of this paper. This research was supported by the National Science Foundation.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Anthony R. Lowry.

Ethics declarations

Competing interests

Reprints and permissions information is available at The author declares no competing financial interests.

Supplementary information

Supplementary Notes

This file describes how to calculate the stress tensor due to surface mass loading anywhere within a radially symmetric Earth, given a known depth variation of density and elastic (Lame's) parameters and the dimensionless load Love numbers hl, ll and kl describing vertical displacement, horizontal displacement and potential respectively. (PDF 30 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Lowry, A. Resonant slow fault slip in subduction zones forced by climatic load stress. Nature 442, 802–805 (2006).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


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.


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