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.

  • Letter
  • Published:

Escape tectonics in the Los Angeles metropolitan region and implications for seismic risk

Nature volume 394, pages 356–360 (1998)Cite this article

Abstract

Recent damaging earthquakes in California, including the 1971 San Fernando1, 1983 Coalinga2, 1987 Whittier Narrows3 and 1994 Northridge4 events, have drawn attention to thrust faults as both potentially hazardous seismic sources and as a mechanism for accommodating shortening in many regions of southern California. Consequently, many geological studies5,6 have concluded that thrust faults in Southern California pose the greatest seismic hazard, and also account for most of the estimated 5–7 mm yr−1 of contraction across the greater Los Angeles metropolitan area7,8 indicated by Global Positioning System geodetic measurements9. Our study demonstrates, however, that less than 50% of the geodetically observed contraction is accommodated on the principal thrust systems across the Los Angeles region. We integrate the most recent geological, geodetic and seismological data to assess the spatial distribution of strain across the Los Angeles metropolitan region. We then demonstrate that a significant component of seismic moment release and shortening in this region is accommodated by east–west crustal escape ‘extrusion’ along known strike-slip and oblique-slip faults.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Figure 1: The main faults of southern California, northern Baja California, Mexico and the Los Angeles metropolitan region are shown on the regional map at the top of the figure.
Figure 2: Geodetic velocity field relative to sites CHIL and BRAN in the San Gabriel and Verdugo mountains.
Figure 3: North–south and east–west cumulative distribution of strain across the Los Angeles metropolitan region based on geological data, geodetic data and our predicted slip rates (Table 1).

Similar content being viewed by others

References

  1. Oakeshott, G. (ed.) San Fernando, California Earthquake of 9 February 1971 (Bull. 196, California Division of Mines and Geology, Sacramento, CA, 1975).

    Google Scholar 

  2. Namson, J. & Davis, T. Seismically active fold and thrust belt in the San Joaquin Valley, central California. Geol. Soc. Am. Bull. 100, 257–273 (1988).

    Article  ADS  Google Scholar 

  3. Hauksson, E. & Jones, L. The Whittier Narrows earthquake sequence in Los Angeles, California: seismological and tectonic analysis. J. Geophys. Res. 94, 9569–9590 (1989).

    Article  ADS  Google Scholar 

  4. Hauksson, E., Jones, L. & Hutton, K. The 1994 Northridge earthquake sequence in California. Seismological and tectonic aspects. J. Geophys. Res. 100, 12335–12355 (1995).

    Article  ADS  Google Scholar 

  5. Shaw, J. H. & Suppe, J. Earthquake hazards of active blind thrust faults under the central Los Angeles basin, California. J. Geophys. Res. 101, 8623–8642 (1996).

    Article  ADS  Google Scholar 

  6. Dolan, J. F. et al. Prospects for larger or more frequent earthquakes in the Los Angeles metropolitan region. Science 267, 199–205 (1995).

    Article  ADS  CAS  Google Scholar 

  7. Feigl, K. L. et al. Space geodetic measurement of crustal deformation in central and southern California, 1984–1992. J. Geophys. Res. 98, 21677–21712 (1993).

    Article  ADS  Google Scholar 

  8. Shen, Z.-K. et al. Crustal deformation across and beyond the Los Angeles basin from geodetic measurements. J. Geophys. Res. 101, 27957–27980 (1996).

    Article  ADS  Google Scholar 

  9. Kleusberg, A. & Teunissen, J. G. GPS for Geodesy (Lecture Notes in Earth Sciences, Springer, 1996).

    Book  Google Scholar 

  10. Phase III Report (Southern California Earthquake Center, Univ. Southern California, Los Angeles, 1996).

  11. Luyendyk, B. Amodel for Neogene crustal rotations, transtension, and transpression in southern California. Geol. Soc. Am. Bull. 103, 1528–1536 (1991).

    Article  ADS  Google Scholar 

  12. Wright, T. L. in Active Margin Basins (ed. Biddle, K. T.) 35–134 (Mem. 52, Am. Assoc. Petroleum Geologists, Tulsa, OK, 1991).

    Google Scholar 

  13. Dickinson, W. Kinematics of transrotational tectonism in the California Transverse Ranges and its contribution to cumulative slip along the San Andreas transform fault system. Geol. Soc. Am. Spec. Pap. 305, 1–50 (1996).

    Google Scholar 

  14. Tsutsumi, H. & Yeats, R. Late Cenozoic structural geology of the 1971 San Fernando and 1994 Northridge earthquake zones in the northern San Fernando Valley, California. Eos 76, F361 (1995).

    Google Scholar 

  15. Hauksson, E. Earthquakes, faulting, and stress in the Los Angeles Basin. J. Geophys. Res. 95, 15365–15394 (1990).

    Article  ADS  Google Scholar 

  16. Mount, S. & Suppe, J. Present-day stress orientations adjacent to active strike-slip faults, California and Sumatra. J. Geophys. Res. 97, 11995–12103 (1992).

    Article  ADS  Google Scholar 

  17. Nicholson, C., Sorlien, C. C., Atwater, T., Crowell, J. C. & Luyendyk, B. P. Microplate capture, rotation of the western Transverse Ranges, and initiation of the San Andreas transform as a low-angle fault system. Geology, Geol. Soc. Am. 22, 491–495 (1994).

    ADS  Google Scholar 

  18. Donnellan, A., Hager, B. H., King, R. W. & Herring, T. A. Geodetic measurement of deformation in the Ventura basin region, southern California. J. Geophys. Res. 98, 21727–21739 (1993).

    Article  ADS  Google Scholar 

  19. Molnar, P. Final report to the Southern California Earthquake Center (Univ. Southern California, Los Angeles, 1992).

    Google Scholar 

  20. Humphreys, E. Tectonics of the greater Los Angeles region: Implications for the lower crust and upper mantle. Eos 76, F347 (1995).

    Article  Google Scholar 

  21. 1. Morton, M. & Matti, J. in Recent Reverse Faulting in the Transverse Ranges, California (eds Morton, D. M. & Yerkes, R. F.) 179–203 (US Geol. Surv. Prof. Pap. 1339, Washington DC, 1987).

    Google Scholar 

  22. Ehlig, P. in San Fernando, California Earthquake of 9 February 1971 (ed. Oakeshott, G. B.) 7–18 (Bull. 196, California Division of Mines and Geology, Sacramento, CA, 1975).

    Google Scholar 

  23. Walls, C., Rockwell, T. K., Pfanner, J., Bornyaxz, M. & Lindvall, S. Uplift gradient along the Sierra Madre-Cucamonga fault zone, Los Angeles, California. Geol. Soc. Am. Abr. Cordilleran Sect. Mtg 29, A–72 (1997).

    Google Scholar 

  24. Bock, Y. Southern California Permanent GPS Geodetic Array. Continuous measurements of crustal deformation between the 1992 Landers and 1994 Northridge earthquakes. J. Geophys. Res. 102, 18013–18033 (1997).

    Article  ADS  Google Scholar 

  25. Bock, Y. & Williams, S. Integrated satellite interferometry in southern California. Eos 78, 293299–293300 (1997).

    Article  Google Scholar 

  26. Crook, R. J., Allen, C. R., Kamb, G., Payne, C. M. & Proctor, R. J. in Recent Reverse Faulting in the Transverse Ranges, California (eds Morton, D. M. & Yerkes, R. F.) 7–26 (US Geol. Surv. Prof. Pap. 1339, Washington DC, 1987).

    Google Scholar 

  27. Hauksson, E. & Jones, L. The 1988 and 1990 Upland earthquakes. Left-lateral faulting adjacent to the central Transverse Ranges. J. Geophys. Res. 96, 8143–8165 (1991).

    Article  ADS  Google Scholar 

  28. Jones, L. M., Sieh, K., Hauksson, E. & Hutton, L. K. The 3 December 1988 Pasadena, California earthquake. Evidence for strike-slip motion on the Raymond fault. Bull. Seismol. Soc. Am. 80, 474–482 (1990).

    Google Scholar 

  29. Penchman, J. in Recent Reverse Faulting in the Transverse Ranges, California (eds Morton, D. M. & Yerkes, R. F.) 97–112 (US Geol. Surv. Prof. Pap. 1339, Washington DC, 1987).

    Google Scholar 

  30. Press, F. & Allen, C. Patterns of seismic release in the southern California region. J. Geophys. Res. 100, 6421–6430 (1995).

    Article  ADS  Google Scholar 

  31. 1. Hutton, L. K., Jones, L. M. & Given, D. D. in Neotectonics of North America (eds Slemmons, D. B., Engdahl, E. R., Zoback, M. D. & Blackwell, D. D.) 133–152 (Geol. Soc. Am., Boulder, CO, 1991).

    Google Scholar 

  32. 2. Zhang, J. et al. Southern California Permanent GPS Geodetic Array. Error analysis of daily position estimates and site velocities. J. Geophys. Res. 102, 18035–18055 (1997).

    Article  ADS  Google Scholar 

  33. McNeilan, T. W., Rockwell, T. K. & Resnick, G. S. Style and rate of Holocene slip, Palos Verdes fault, southern California. J. Geophys. Res. 101, 8317–8334 (1996).

    Article  ADS  Google Scholar 

  34. Rockwell, T., Gath, E. M. & Gonzalez, T. Sense and rate of slip on the Whittier fault zone, eastern Los Angeles Basin, CA. Assoc. Eng. Geol. Abstr. 35, 679 (1992).

    Google Scholar 

  35. Bergmann, M. & Rockwell, T. Preliminary assessment of the late Holocene slip rate for the Wildomar fault in Murrieta, California. Assoc. Eng. Geol. Abstr. Programs 36, 43 (1993).

    Google Scholar 

  36. Grant, L. B., Waggoner, J. T., Rockwell, T. & von Stein, C. Paleoseismicity of the north branch of the Newport-Inglewood fault zone in Huntington Beach, California, from cone penetrometer test data. Bull. Seismol. Soc. Am. 87, 277–293 (1997).

    Google Scholar 

  37. Oskin, M. & Sieh, K. The Elysian Park anticlinorium: Surficial evidence of an active blind reverse fault beneath downtown Los Angeles. Geol. Soc. Am. Abr. Cordilleran Sect. Mtg 30, A–57 (1998).

    Google Scholar 

  38. Yeats, R. S. & Huftile, G. J. The Oak Ridge fault system and the 1994 Northridge earthquake. Nature 373, 418–420 (1995).

    Article  ADS  CAS  Google Scholar 

  39. Dolan, J., Sieh, K., Rockwell, T. K., Guptill, P. & Miller, G. Active tectonics, paleoseismology, and seismic hazards of the Hollywood fault, northern Los Angeles basin, California. Geol. Soc. Am. Bull. 109, 1595–1616 (1997).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank J. Shaw, C. Nicholson and R. Yeats for criticisms and suggestions, and the Southern California Integrated GPS Network and International GPS Service for continuous GPS data. This work was supported by the Southern California Earthquake Center.

Author information

Author notes

  1. Christian Walls

    Present address: Earth Consultants International, 2522 N. Santiago Blvd, Suite B, Orange, California, 92867, USA

Authors and Affiliations

  1. Department of Geological Sciences, San Diego State University, 92182, California, USA

    Christian Walls, Thomas Rockwell & John Pfanner

  2. Southern California Earthquake Center, University of Southern California, Los Angeles, 90089-0740, California, USA

    Christian Walls, Thomas Rockwell, Karl Mueller, Yehuda Bock, Simon Williams, John Pfanner, James Dolan & Peng Fang

  3. Department of Geological Sciences, University of Colorado, Boulder, 80309, Colorado, USA

    Karl Mueller

  4. IGPP, Scripps Institution of Oceanography, La Jolla, 92093, California, USA

    Yehuda Bock, Simon Williams & Peng Fang

  5. Department of Geological Sciences, University of Southern California, Los Angeles, 90089, California, USA

    James Dolan

Authors
  1. Christian Walls
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Thomas Rockwell
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Karl Mueller
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Yehuda Bock
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Simon Williams
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. John Pfanner
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. James Dolan
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Peng Fang
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Christian Walls.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Walls, C., Rockwell, T., Mueller, K. et al. Escape tectonics in the Los Angeles metropolitan region and implications for seismic risk. Nature 394, 356–360 (1998). https://doi.org/10.1038/28590

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/28590

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

Advanced 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