Abstract
Large earthquakes on mid-ocean ridge transform faults are commonly preceded by foreshocks1,2,3 and changes in the seismic properties of the fault zone3. These seismic precursors could be linked to fluid-related processes2,3. Hydrothermal fluids within young, hot crust near the intersection of oceanic transform faults become significantly more compressible with decreasing pressure, with potential impacts on fault behaviour. Here we use a theoretical model to show that oceanic transform faults can switch from dilatant and progressive deformation to rupture in response to fluid-related processes. We assume that the fault core material behaves according to a dilatant and strain-softening or contractant and strain-hardening constitutive law (Cam-clay-type4), depending on the effective stress state. According to our model, after the initial purely rigid-elastic phase, dilatancy is found to occur within the fault core, causing pore pressure to decrease, hence fluid compressibility to increase. The plastic regime starts with a stable phase, with effective stresses gradually increasing over a timescale of years in response to tectonic loading. The fault then evolves into a metastable phase, lasting a few days, as the pore pressure decreases, inducing large variations or even a discontinuous jump in fluid compressibility, depending on fluid properties. This in turn triggers fault-slip instability that creates foreshock swarms. In the final phase, the fault fails in the mainshock rupture. Our results imply that seismic precursors are caused by the decrease in fluid pressure which results in an increase in fluid compressibility, in response to fault core dilatancy just before rupture.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Change history
24 December 2015
The version of this Letter originally published described hydrothermal fluids circulating within oceanic fracture zones near ridgetransform intersections as super-critical fluids. However, Daniel Broseta, Matthew Steele-MacInnis and Thomas Driesner pointed out that, even if this term is of common use in the scientific literature, this description is incorrect and potentially misleading for multicomponent fluids such as seawater. In addition, some of the values of compressibility cited in the original Letter were incorrect. Correct values of isothermal compressibility of seawater are one order of magnitude higher compared with those used in the original manuscript and exhibit a sharp discontinuous increase near dew-point conditions. As a consequence, the effect of variations in fluid compressibility on seismicity is enhanced. This strengthens our confidence in the Piau-Maury-Fitzenz model. Figures 2 and 3 and some of the calculations invoking the real fluid properties at the relevant conditions have been corrected in all online versions of the Letter. Daniel Broseta, Matthew Steele-MacInnis and Thomas Driesner have been added to the author list in recognition of their contributions to these amendments.
References
Dziak, R. P., Chadwick, W. W. Jr, Fox, C. G. & Embley, R. W. Hydrothermal temperature changes at the Southern Juan de Fuca Ridge associated with Mw 6.2 Blanco transform earthquake. Geology 31, 119–122 (2003).
McGuire, J. J., Boettcher, M. S. & Jordan, T. H. Foreshock sequences and short-term earthquake predictability on East Pacific Rise transform faults. Nature 434, 457–461 (2005).
McGuire, J. J. et al. Variations in earthquake rupture properties along the Gofar transform fault, East Pacific Rise. Nature Geosci. 5, 336–341 (2012).
Roscoe, K. H. & Burland, J. B. On the Generalized Stress–Strain Behavior of ‘Wet’ Clay 535–609 (Cambridge Univ. Press, 1968).
Kanamori, H. & Stewart, G. S. Mode of the strain release along the Gibbs fracture zone, Mid-Atlantic ridge. Phys. Earth Planet. Inter. 11, 312–332 (1976).
Okal, E. A. & Stewart, L. M. Slow earthquakes along oceanic fracture zones: Evidence for asthenospheric flow away from hotspots? Earth Planet. Sci. Lett. 57, 75–87 (1982).
Ihmlé, P. & Jordan, T. H. Teleseismic search for slow precursors to large earthquakes. Science 266, 1547–1551 (1994).
Abercombrie, R. & Ekström, G. Earthquake slip on oceanic transform faults. Nature 410, 74–77 (2001).
Abercombrie, R. & Ekström, G. A reassessment of the rupture characteristics of oceanic transform earthquakes. J. Geophys. Res. 108, 2225 (2003).
Fox, C. G., Dziak, R. P., Matsumoto, H. & Schreiner, A. E. Potential for monitoring low-level seismicity on the Juan de Fuca Ridge using military hydrophone arrays. Mar. Technol. Soc. J. 27, 22–30 (1994).
Ben-Zion, Y. et al. A shallow fault-zone structure illuminated by trapped waves in the Karadere-Duzce branch of the North-Anatolian Fault, Western Turkey. Geophys. J. Int. 152, 699–717 (2003).
Fialko, Y. Probing the mechanical properties of seismically active crust with space geodesy: Study of the coseismic deformation due to the 1992 Mw 7.3 Landers (South California) earthquake. J. Geophys. Res. 109, 1–19 (2004).
Peng, Z. et al. Quantitative analysis of seismic fault zone waves in the rupture zone of the 1992 Landers, California, earthquake: Evidence for a shallow trapping structure. Geophys. J. Int. 155, 1021–1041 (2003).
Lockner, D. et al. Permeability and Strength of Core Samples for the Nojima Fault of the 1995 Kobe Earthquake. Report No. 0F 00-0129 147–152 (US Geological Survey, 2000).
Maury, V., Piau, J-M. & Fitzenz, D. in Harmonising Rock Engineering and the Environment (12th ISRM Internat. Congress on Rock Mechanics Beijing Oct. 2011) (eds Qian, Q. & Zhou, Y.) (CRC Press, 2011)available at http://dx.doi.org/10.13140/2.1.1077.1849.
Roscoe, K. H., Schofield, A. N. & Wroth, C. P. On the yielding of soils. Geotechnique 8, 22–53 (1958).
Schofield, A. N. & Wroth, C. P. Critical State Soil Mechanics (McGraw-Hill, 1968).
Dieterich, J. H. Time dependent friction and the mechanics of stick-slip. Pure Appl. Geophys. 116, 790–806 (1978).
Ruina, A. Slip instability and state variable friction laws. J. Geophys. Res. 88, 10359–10370 (1983).
Segall, P. Rice, Dilatancy, compaction and slip instability of a fluid infiltrated fault. J. Geophys. Res. 100, 22155–22171 (1995).
Davis, E. E. et al. Hydrological response to a sea-floor spreading episode of the Juan de Fuca Ridge. Nature 430, 335–338 (2004).
Guéguen, Y. & Palciauskas, V. Introduction à La Physique Des Roches 299 (Hermann, Paris, 1992).
Embley, R. W. & Wilson, D. S. Morphology of the Blanco Transform Fault, northeast Pacific. Implications for its tectonic evolution. Mar. Geophys. Res. 14, 25–45 (1992).
Juteau, T. et al. A submersible study in the Western Blanco fracture zone: Structure and evolution during the last 1.6 Ma. Mar. Geophys. Res. 17, 399–430 (1995).
Bischoff, J. L. & Rosenbauer, R. J. An empirical equation of state for hydrothermal seawater (3.2 percent NaCl). Am. J. Sci. 285, 725–763 (1985).
Koshinsky et al. Hydrothermal venting at pressure–temperature conditions above the critical point of seawater, 5° S on the Mid-Atlantic Ridge. Geology 36, 615–618 (2008).
Driesner, T. & Heinrich, C.A. The system H2O–NaCl. Part I: Correlation formulae for phase relations in temperature–pressure–composition space from 0 to 1000 °C, 0 to 5000 bar, and 0 to 1 XNaCl. Geochim. Cosmochim. Acta 71, 4880–4901 (2007).
Driesner, T. The system H2O–NaCl. Part II: Correlations for molar volume, enthalpy, and isobaric heat capacity from 0 to 1000 °C, 1 to 5000 bar, and 0 to 1 XNaCl. Geochim. Cosmochim. Acta 71, 4902–4919 (2007).
Acknowledgements
This work is a tribute to late Jean Francheteau, who passed away on 21 July, 2010. Jean supported the ideas developed in this paper since the very beginning. The work was initiated in 2005, when L.G. was a Cecil and Ida Green Scholar at IGPP/SIO, University of California, San Diego, at the invitation of J. Orcutt and M. Zumberge, who are both greatly acknowledged here. Discussions with Y. Fialko, Y. Hamiel and J. Sclater were very useful. This paper is NOAA/PMEL contribution number 4109.
Author information
Authors and Affiliations
Contributions
L.G. initiated the work based on previous work by R.D., who provided the initial dataset from the Blanco FZ and greatly contributed to the ideas developed in the manuscript. L.G. and P.H. discussed different models, before employing the Piau–Maury–Fitzenz model, produced by J-M.P., V.M. and D.F. D.B., M.S.-M. and T.D. pointed out the thermomechanical effects of phase changes for multi-component fluids. J-M.P. wrote Supplementary Appendix 2. L.G. wrote Supplementary Appendix 3, with contributions from Q.C. and V.M. All authors discussed results and contributed to the manuscript.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Supplementary Information
Supplementary Information (PDF 2286 kb)
Rights and permissions
About this article
Cite this article
Géli, L., Piau, JM., Dziak, R. et al. Seismic precursors linked to highly compressible fluids at oceanic transform faults. Nature Geosci 7, 757–761 (2014). https://doi.org/10.1038/ngeo2244
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/ngeo2244
This article is cited by
-
Gas and seismicity within the Istanbul seismic gap
Scientific Reports (2018)
-
Erratum: Corrigendum: Seismic precursors linked to highly compressible fluids at oceanic transform faults
Nature Geoscience (2016)
