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.

  • Letter
  • Published:

Extent, duration and speed of the 2004 Sumatra–Andaman earthquake imaged by the Hi-Net array


The disastrous Sumatra–Andaman earthquake of 26 December 2004 was one of the largest ever recorded. The damage potential of such earthquakes depends on the extent and magnitude of fault slip. The first reliable moment magnitude estimate1 of 9.0 was obtained several hours after the Sumatra–Andaman earthquake, but more recent, longer-period, normal-mode analyses have indicated that it had a moment magnitude of 9.3, about 2.5 times larger2. Here we introduce a method for directly imaging earthquake rupture that uses the first-arriving compressional wave and is potentially able to produce detailed images within 30 min of rupture initiation. We used the Hi-Net seismic array in Japan as an antenna to map the progression of slip by monitoring the direction of high-frequency radiation. We find that the rupture spread over the entire 1,300-km-long aftershock zone by propagating northward at roughly 2.8 km s-1 for approximately 8 minutes. Comparisons with the aftershock areas of other great earthquakes indicate that the Sumatra–Andaman earthquake did indeed have a moment magnitude of 9.3. Its rupture, in both duration and extent, is the longest ever recorded.

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

Access options

Buy this article

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

Figure 1: Earthquake and station distribution.
Figure 2: Rupture progression.
Figure 3: Rupture speed and energy release.
Figure 4: Cumulative radiated energy.
Figure 5: Comparison of aftershock zones of great earthquakes.

Similar content being viewed by others


  1. Dziewonski, A. M. & Woodhouse, J. H. An experiment in systematic study of global seismicity: Centroid-moment tensor solutions for 201 moderate and large earthquakes of 1981. J. Geophys. Res. 88, 3247–3271 (1983)

    Article  ADS  Google Scholar 

  2. Stein, S. & Okal, E. A. Speed and size of the Sumatra earthquake. Nature 434, 581–582 (2005)

    Article  ADS  CAS  Google Scholar 

  3. Ni, S., Kanamori, H. & Helmberger, D. Energy radiation from the Sumatra earthquake. Nature 434, 582 (2005)

    Article  ADS  CAS  Google Scholar 

  4. National Research Institute for Earth Science and Disaster Prevention. (2005).

  5. Ellsworth, W. L. Imaging fault rupture without inversion. Seismol. Res. Lett. 63, 73 (1992)

    Google Scholar 

  6. Spudich, P. & Cranswick, E. Direct observation of rupture propagation during the Imperial Valley earthquake using a short baseline accelerometer array. Bull. Seismol. Soc. Am. 74, 2083–2114 (1984)

    Google Scholar 

  7. Ortiz, M. & Bilham, R. Source area and rupture parameters of the 31 December 1881 Mw = 7.9 Car Nicobar earthquake estimated from tsunamis recorded in the Bay of Bengal. J. Geophys. Res. 108 (2003) doi:10.1029/2002JB001941

  8. Houston, H. & Kanamori, H. Source spectra of great earthquakes: Teleseismic constraints on rupture process and strong ground motion. Bull. Seismol. Soc. Am. 76, 19–42 (1986)

    Google Scholar 

  9. Kanamori, H. & Cipar, J. J. Focal process of the great Chilean earthquake May 22, 1960. Phys. Earth Planet. Inter. 9, 128–136 (1974)

    Article  ADS  Google Scholar 

  10. Christensen, D. H. & Beck, S. L. The rupture process and tectonic implications of the great 1964 Prince-William-Sound earthquake. Pure Appl. Geophys. 142, 29–53 (1994)

    Article  ADS  Google Scholar 

  11. Johnson, J. M. et al. The 1957 great Aleutian earthquake. Pure Appl. Geophys. 142, 3–28 (1994)

    Article  ADS  Google Scholar 

  12. Beck, S. L. & Christensen, D. H. Rupture process of the February 4, 1965, Rat Islands earthquake. J. Geophys. Res. 96, 2205–2221 (1991)

    Article  ADS  Google Scholar 

  13. McGuire, J. J., Zhao, L. & Jordan, T. H. Predominance of unilateral rupture for a global catalog of large earthquakes. Bull. Seismol. Soc. Am. 92, 3309–3317 (2002)

    Article  Google Scholar 

  14. Kanamori, H. & Brodsky, E. E. The physics of earthquakes. Rep. Prog. Phys. 67, 1429–1496 (2004)

    Article  ADS  MathSciNet  Google Scholar 

  15. Kanamori, H. The energy release in great earthquakes. J. Geophys. Res. 82, 2981–2987 (1977)

    Article  ADS  Google Scholar 

  16. Shearer, P. M. & Earle, P. S. The global short-period wavefield modelled with a Monte Carlo seismic phonon method. Geophys. J. Int. 158, 1103–1117 (2004)

    Article  ADS  Google Scholar 

  17. Kennett, B. L. N. IASPEI 1991 Seismological Tables (Research School of Earth Sciences, Australia National University, Canberra, Australia, 1991)

    Book  Google Scholar 

  18. Brazee, R. J. & Cloud, W. K. United States Earthquakes 1957 (US Coast and Geodetic Survey, Washington DC, 1959)

    Google Scholar 

  19. Algermissen, S. T., Rinehart, W. A., Sherburne, R. W. & Dillinger, W. H. The Great Alaska Earthquake of 1964 313–364 (National Academy of Sciences, Washington DC, 1972)

    Google Scholar 

  20. Talley, J. H. C. & Cloud, W. K. United States Earthquakes 1960 (US Coast and Geodetic Survey, Washington DC, 1962)

    Google Scholar 

Download references


We thank the National Research Institute for Earth Science and Disaster Prevention in Japan for making the Hi-Net data available on the Internet.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Miaki Ishii.

Ethics declarations

Competing interests

Reprints and permissions information is available at The authors declare no competing financial interests.

Supplementary information

Supplementary Figure S1

Cumulative radiated energy (as in main text Figure 4), but using synthetic seismograms with point sources at six locations indicated by black stars and spaced at 100 s interval. (DOC 140 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Ishii, M., Shearer, P., Houston, H. et al. Extent, duration and speed of the 2004 Sumatra–Andaman earthquake imaged by the Hi-Net array. Nature 435, 933–936 (2005).

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