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.

The 2011 Lorca earthquake slip distribution controlled by groundwater crustal unloading


Earthquake initiation, propagation and arrest are influenced by fault frictional properties1,2 and preseismic stress3,4. Studies of triggered and induced seismicity5,6,7 can provide unique insights into this influence. However, measurements of near-field, surface ground deformation8,9 and pre-earthquake stress conditions necessary for such studies are rare. Here, we use geodetic data to determine surface deformation associated with the Mw 5.1 earthquake that occurred in Lorca, southeast Spain, on 11 May 2011. We use an elastic dislocation model to show that earthquake nucleation and the area of main fault slip occurred at very shallow depths of 2–4 km, on a rupture plane along the Alhama de Murcia Fault. Slip extended towards the surface, across fault segments with frictional properties that changed from unstable to stable. The area of fault slip correlates well with the pattern of positive Coulomb stress change that we calculate to result from the extraction of groundwater in a nearby basin aquifer. We therefore suggest that the distribution of shallow slip during the Lorca earthquake could be controlled by crustal unloading stresses at the upper frictional transition of the seismogenic layer, induced by groundwater extraction. Our results imply that anthropogenic activities could influence how and when earthquakes occur.

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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout

Figure 1: Location and kinematics of the Lorca earthquake.
Figure 2: Ground deformation data and model.
Figure 3: Fault slip and unloading stress change models.


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

    Article  Google Scholar 

  2. Marone, C. & Scholz, C. H. The depth of seismic faulting and the upper transition from stable to unstable slip regimes. Geophys. Res. Lett. 15, 621–624 (1988).

    Article  Google Scholar 

  3. Kaneko, Y., Avouac, J-P. & Lapusta, N. Towards inferring earthquake patterns from geodetic observations of interseismic coupling. Nature Geosci. 3, 365–369 (2010).

    Article  Google Scholar 

  4. Loveless, J. P. & Meade, B. J. Spatial correlation of interseismic coupling and coseismic rupture extent of the 2011 Mw = 9.0 Tohoku-oki earthquake. Geophys. Res. Lett. 38, L17306 (2011).

    Article  Google Scholar 

  5. Simpson, D. W. Triggered earthquakes. Annu. Rev. Earth Planet Sci. 14, 21–42 (1986).

    Article  Google Scholar 

  6. Seeber, L., Armbruster, J. G., Kim, W-Y., Barstow, N. & Scharnberger, C. The 1994 Cacoosing Valley earthquakes near Reading, Pennsylvania: A shallow rupture triggered by quarry unloading. J. Geophys. Res. 103, 24505–24521 (1998).

    Article  Google Scholar 

  7. McCarr, A., Simpson, D. & Seeber, L. in International Handbook of Earthquake and Engineering Seismology vol. 81A (eds Lee, W. H. K., Kanamori, H., Jennings, P. C. & Kisslinger, C.) (Academic, 2002).

    Google Scholar 

  8. Fialko, Y., Sandwell, D., Simons, M. & Rosen, P. Three-dimensional deformation caused by the Bam, Iran, earthquake and the origin of shallow slip deficit. Nature 435, 295–299 (2005).

    Article  Google Scholar 

  9. Fielding, E. J., Lundgren, P. L., Bürgmann, R. & Funning, G. J. Shallow fault-zone dilatancy recovery after the 2003 Bam earthquake in Iran. Nature 458, 64–68 (2009).

    Article  Google Scholar 

  10. Stich, D., Serpelloni, E., Mancilla, F. & Morales, J. Kinematics of the Iberia-Maghreb plate contact from seismic moment tensors and GPS observations. Tectonophysics 426, 295–317 (2006).

    Article  Google Scholar 

  11. Masana, E., Martı´nez-Dı´az, J. J., Hernández-Enrile, J. L. & Santanach, P. The Alhama de Murcia fault (southwest Spain), a seismogenic fault in a diffuse plate boundary: Seismotectonic implications for the Ibero-Magrebian region. J. Geophys. Res. 109, B01301 (2004).

    Article  Google Scholar 

  12. IGN, Informe del sismo de Lorca del 11 de Mayo de 2011 [in Spanish] (, 2011).

  13. Lopez-Comino, J. A., Mancilla, F. d. L., Morales, J. & Stich, D. Rupture directivity of the 2011, Mw 5.2 Lorca earthquake (Spain). Geophys. Res. Lett. 39, L03301 (2012).

    Article  Google Scholar 

  14. González, P. J. & Fernández, J. Drought-driven transient aquifer compaction imaged using multitemporal satellite radar interferometry. Geology 39, 551–554 (2011).

    Article  Google Scholar 

  15. Okada, Y. Surface deformation due to shear and tensile faults in a half-space. Bull. Seismol. Soc. Am. 75, 1135–1154 (1985).

    Google Scholar 

  16. González, P. J., Tiampo, K. F., Camacho, A. G. & Fernández, J. Shallow flank deformation at Cumbre Vieja volcano (Canary Islands): Implications on the stability of steep-sided volcano flanks at oceanic islands. Earth Planet. Sci. Lett. 297, 545–557 (2010).

    Article  Google Scholar 

  17. Frontera, T. et al. DInSAR coseismic deformation of the May 2011 Mw 5.1 Lorca earthquake (southeastern Spain). Solid Earth 3, 111–119 (2012).

    Article  Google Scholar 

  18. Martı´nez-Dı´az, J. J. Stress field variations related to fault interaction in a reverse oblique-slip fault: The Alhama de Murcia fault, Betic Cordillera, Spain. Tectonophysics 356, 291–305 (2002).

    Article  Google Scholar 

  19. Hooper, A. et al. Increased capture of magma in the crust promoted by ice-cap retreat in Iceland. Nature Geosci. 4, 783–786 (2011).

    Article  Google Scholar 

  20. Heki, K. Snow load and seasonal variation of earthquake occurrence in Japan. Earth Planet. Sci. Lett. 207, 159–164 (2003).

    Article  Google Scholar 

  21. Klose, C. D. Geomechanical modeling of the nucleation process of Australia’s 1989 M5.6 Newcastle earthquake. Earth Planet. Sci. Lett. 256, 547–553 (2007).

    Article  Google Scholar 

  22. Bettinelli, P. et al. Seasonal variations of seismicity and geodetic strain in the Himalaya induced by surface hydrology. Earth Planet. Sci. Lett. 266, 332–344 (2008).

    Article  Google Scholar 

  23. Cerón, J. C. & Pulido-Bosch, A. Groundwater problems resulting from CO2 pollution and overexploitation in Alto Guadalentı´n aquifer (Murcia, Spain). Environ. Geol. 28, 223–228 (1996).

    Article  Google Scholar 

  24. Boussinesq, J. Application des Potentiels à l’Étude de l’Équilibre et du Mouvement des Solides Élastiques (Reprint Paris: Blanchard, 1969, (1885)).

  25. Rueda, J., Mezcua, J. & Garcia Blanco, R. M. Directivity effects of the May 11, 2011 Lorca (Spain) Mw = 5.1 earthquake, S53B-2277, 2011 Fall Meeting, AGU, San Francisco, California, 5–9 Dec. (2011).

  26. Marone, C., Scholz, C. & Bilham, R. On the mechanics of earthquake afterslip. J. Geophys. Res. 96, 8441–8452 (1991).

    Article  Google Scholar 

  27. Hetzel, R. & Hampel, A. Slip rate variations on normal faults during glacial-interglacial changes in surface loads. Nature 435, 486–492 (2011).

    Google Scholar 

  28. Brothers, D., Kilb, D., Luttrell, K., Driscoll, N. & Kent, G. Loading of the San Andreas fault by flood-induced rupture of faults beneath the Salton Sea. Nature Geosci. 4, 486–492 (2011).

    Article  Google Scholar 

  29. Hampel, A., Hetzel, R., Maniatis, G. & Karow, T. Three-dimensional numerical modeling of slip rate variations on normal and thrust fault arrays during ice cap growth and melting. J. Geophys. Res. 114, B08406 (2008).

    Google Scholar 

  30. González, P.J. & Fernández, J. Error estimation in multitemporal InSAR deformation time series, with application to Lanzarote, Canary Islands. J. Geophys. Res. 116, B10404 (2011).

    Article  Google Scholar 

Download references


Our research was financially supported by an Ontario Early Researcher Award, the CSRN NSERC Strategic Network Grant, and the NSERC and Aon Benfield/ICLR IRC in Earthquake Hazard Assessment. P.J.G. also acknowledges the Banting Postdoctoral Fellowship of the Government of Canada. Further support was provided by the projects CGL2005-05500-C02, CGL2008-06426-C01-01/BTE, PCI2006-A7-0660 and AYA2010-17448; as well the Moncloa International Campus of Excellence. Radar data were from ESA CAT1:4460 and 6745 projects. GPS data were from Meristemum, Red Activa de Murcia and IGN networks. GMT software was used to create all figures. We are grateful to J-P. Avoua for helpful comments. We thank P. Bhattacharya, N. Cho and F. Lorenzo-Martı´n for stimulating discussions, F. Luzón, and J. Morales and A. Concha for sharing manuscripts before publication13,17.

Author information

Authors and Affiliations



P.J.G. carried out the radar data analysis; dislocation, loading and pore-pressure diffusion models; and wrote the manuscript with the help of all co-authors. K.F.T. and P.J.G. carried out the CFF models. M.P. processed daily GPS data and computed the two-dimensional strain-rate tensor. F.C. processed high-rate GPS data and analysed accelerometer frequency spectra. J.F. and P.J.G. designed the research.

Corresponding author

Correspondence to Pablo J. González.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 13576 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

González, P., Tiampo, K., Palano, M. et al. The 2011 Lorca earthquake slip distribution controlled by groundwater crustal unloading. Nature Geosci 5, 821–825 (2012).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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