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The 2009 Samoa–Tonga great earthquake triggered doublet

Nature volume 466, pages 964–968 (2010)Cite this article

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Abstract

Great earthquakes (having seismic magnitudes of at least 8) usually involve abrupt sliding of rock masses at a boundary between tectonic plates. Such interplate ruptures produce dynamic and static stress changes that can activate nearby intraplate aftershocks, as is commonly observed in the trench-slope region seaward of a great subduction zone thrust event1,2,3,4. The earthquake sequence addressed here involves a rare instance in which a great trench-slope intraplate earthquake triggered extensive interplate faulting, reversing the typical pattern and broadly expanding the seismic and tsunami hazard. On 29 September 2009, within two minutes of the initiation of a normal faulting event with moment magnitude 8.1 in the outer trench-slope at the northern end of the Tonga subduction zone, two major interplate underthrusting subevents (both with moment magnitude 7.8), with total moment equal to a second great earthquake of moment magnitude 8.0, ruptured the nearby subduction zone megathrust. The collective faulting produced tsunami waves with localized regions of about 12 metres run-up that claimed 192 lives in Samoa, American Samoa and Tonga. Overlap of the seismic signals obscured the fact that distinct faults separated by more than 50 km had ruptured with different geometries, with the triggered thrust faulting only being revealed by detailed seismic wave analyses. Extensive interplate and intraplate aftershock activity was activated over a large region of the northern Tonga subduction zone.

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Figure 1: The Samoa–Tonga great earthquake doublet region.
Figure 2: Observed and modelled R1 STFs.
Figure 3: P-wave back-projection using the Japanese F-Net stations.
Figure 4: Surface wave modelling for simple and composite models.

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References

  1. Christensen, D. H. & Ruff, L. J. Seismic coupling and outer rise earthquakes. J. Geophys. Res. 93, 13421–13444 (1988)

    Article  ADS  Google Scholar 

  2. Dmowska, R., Rice, J. R., Lovison, L. C. & Josell, D. Stress transfer and seismic phenomena in coupled subduction zones during the earthquake cycle. J. Geophys. Res. 93, 7869–7884 (1988)

    Article  ADS  Google Scholar 

  3. Lay, T., Astiz, L., Kanamori, H. & Christensen, D. H. Temporal variation of large intraplate earthquakes in coupled subduction zones. Phys. Earth Planet. Inter. 54, 258–312 (1989)

    Article  ADS  Google Scholar 

  4. Ammon, C. J., Kanamori, H. & Lay, T. A great earthquake doublet and seismic stress transfer cycle in the central Kuril islands. Nature 451, 561–566 (2008)

    Article  CAS  ADS  Google Scholar 

  5. Kanamori, H. Seismological evidence for a lithospheric normal faulting; the Sanriku earthquake of 1933. Phys. Earth Planet. Inter. 4, 289–300 (1971)

    Article  ADS  Google Scholar 

  6. Lynnes, C. S. & Lay, T. Source process of the great 1977 Sumba earthquake. J. Geophys. Res. 93, 13407–13420 (1988)

    Article  ADS  Google Scholar 

  7. Taylor, M. A. J., Zheng, G., Rice, J. R., Stuart, W. D. & Dmowska, R. Cyclic stressing and seismicity at strong coupled subduction zones. J. Geophys. Res. 101, 8363–8381 (1996)

    Article  ADS  Google Scholar 

  8. Lay, T. et al. The 2006–2007 Kuril Islands great earthquake sequences. J. Geophys. Res. 114 B11308 10.1029/2008JB006280 (2009)

    Article  ADS  Google Scholar 

  9. Ranero, C. R., Villaseñor, A., Phipps Morgan, J. & Weinrebe, W. Relationship between bend-faulting at trenches and intermediate-depth seismicity. Geochem. Geophys. Geosyst. 6 Q12002 10.1029/2005GC000997 (2005)

    Article  ADS  Google Scholar 

  10. Faccenda, M., Gerya, T. V. & Burlini, L. Deep slab hydration induced by bending-related variations in tectonic pressure. Nature Geosci. 2, 790–793 (2009)

    Article  CAS  ADS  Google Scholar 

  11. Earthquake. Hazards Program. Magnitude 8.1—Samoa Islands region. 〈http://earthquake.usgs.gov/eqcenter/eqinthenews/2009/us2009mdbi/#details〉 (US Geological Survey, 2009)

  12. Jaffe, B. Surprises from the deadly September 29, 2009, Samoa tsunami. 〈http://soundwaves.usgs.gov/2009/12/〉 (US Geological Survey, 2009)

  13. NOAA Center for Tsunami Research. Tsunami event—September 29, 2009 Samoa. http://nctr.pmel.noaa.gov/samoa20090929/ (2009)

  14. Iida, K., Cox, D. C. & Pararas-Carayannis, G. Preliminary catalog of tsunamis occurring in the Pacific Ocean. Data Report 5, HIG-67–10, 261 (Hawaii Institute of Geophysics, University of Hawaii, 1967)

  15. Gutenberg, B. & Richter, C. F. Seismicity of the Earth and Associated Phenomena 2nd edn (Princeton University Press, 1954)

    Google Scholar 

  16. Okal, E. & Kirby, S. H. Large earthquakes and tsunamis at the Samoa corner in the context of the 2009 Samoa event. Eos 90 (52), (Fall Meet. Suppl.), abstr. U21E–2182 (2009)

  17. Ekström, G. & Nettles, M. Global Centroid-Moment-Tensor Project. 〈http://www.globalcmt.org/〉 (National Science Foundation, 2009)

  18. Kanamori, H. & Rivera, L. Source inversion of W-phase: speeding up seismic tsunami warning. Geophys. J. Int. 175, 222–238 (2008)

    Article  ADS  Google Scholar 

  19. Fujii, Y. & Satake, K. Samoa Islands Tsunami on Sep. 29, 2009. http://iisee.kenken.go.jp/staff/fujii/Samoa/tsunami.html (2009)

  20. Tonini, R., Pagnoni, G., Armigliato, A. & Tinti, S. The 29th September Samoa islands tsunami: preliminary simulations based on the first focal mechanisms hypotheses and implications of uncertainties in tsunami early warning strategies. Eos 90(52), (Fall Meet. Suppl.), abstr. U21E–2185 (2009)

  21. Hill, D. P. et al. Remote seismicity triggered by the M7.5 Landers, California earthquake of June 28, 1992. Science 260, 1617–1623 (1993)

    Article  CAS  ADS  Google Scholar 

  22. Velasco, A. A., Hernandez, S., Parsons, T. & Pankow, K. Global ubiquity of dynamic earthquake triggering. Nature Geosci. 1, 375–379 (2008)

    Article  CAS  ADS  Google Scholar 

  23. Umino, N., Kono, T., Hasegawa, A. & Tamura, Y. Revisiting the 1933 off Sanriku earthquake (M8.1) by using smoked-paper seismographs. Ann. Meet. Seismol. Soc. Jpn abstr. [in Japanese] (2007)

  24. Li, X., Shao, G. & Ji, C. Rupture process of the 2009 Mw 8.1 Samoa earthquake constrained by joint inverting teleseismic body, surface waves and local strong motion. Eos (Fall Meet.) abstr. U21D–03 (2009).

  25. Scholz, C. Earthquakes and friction laws. Nature 391, 37–42 (1998)

    Article  CAS  ADS  Google Scholar 

  26. Ishii, M., Shearer, P. M., Houston, H. & Vidale, J. E. Extent, duration and speed of the 2004 Sumatra-Andaman earthquake imaged by the Hi-net array. Nature 435, 933–936 (2005)

    Article  CAS  ADS  Google Scholar 

  27. Xu, Y., Koper, K. D., Sufri, O., Zhu, L. & Hutko, A. R. Rupture imaging of the Mw 7.9 12 May 2008 Wenchuan earthquake from back projection of teleseismic P waves. Geochem. Geophys. Geosyst. 10 Q04006 10.1029/2008GC002335 (2009)

    Article  ADS  Google Scholar 

  28. Hartzell, S. H. & Heaton, T. H. Inversion of strong ground motion and teleseismic waveform data for the fault rupture history of the 1979 Imperial Valley, California, earthquake. Bull. Seismol. Soc. Am. 73, 1153–1184 (1983)

    Google Scholar 

  29. Kikuchi, M. & Kanamori, H. Inversion of complex body waves. Bull. Seismol. Soc. Am. 81, 2335–2350 (1991)

    Google Scholar 

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

    Article  ADS  Google Scholar 

  31. Boschi, L. & Ekström, G. New images of the Earth’s upper mantle from measurements of surface-wave phase velocity anomalies. J. Geophys. Res. 107, S1, 10.1029/2000JB000059 (2002).

    Article  Google Scholar 

  32. Kennett, B. L. N., Engdahl, E. R. & Buland, R. Constraints on seismic velocities in the earth from travel times. Geophys. J. Int. 122, 108–124 (1995)

    Article  ADS  Google Scholar 

  33. VanDecar, J. C. & Crosson, R. S. Determination of teleseismic phase arrival times using multi-channel cross correlation and least squares. Bull. Seismol. Soc. Am. 80, 150–169 (1990)

    Google Scholar 

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Acknowledgements

This work made use of GMT and SAC software and Federation of Digital Seismic Networks (FDSN) seismic data. The Incorporated Research Institutions for Seismology (IRIS) Data Management System (DMS) and the F-Net and Hi-Net data centres were used to access the data. C. Ji kindly shared details of his model. Z. Duputel wrote the W-Phase software version used in this study. We thank H. Savage and E. Brodsky for discussions of frictional conditional stability. This work was supported by NSF grant EAR0635570 and USGS Award Number 05HQGR0174.

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Authors and Affiliations

  1. Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, 95064, California, USA

    Thorne Lay

  2. Department of Geosciences, The Pennsylvania State University, 440 Deike Building, University Park, Pennsylvania 16802, USA,

    Charles J. Ammon

  3. Seismological Laboratory, California Institute of Technology, MS 252-21, Pasadena, California 91125, USA,

    Hiroo Kanamori

  4. Institut de Physique du Globe de Strasbourg, UMR7516, Université de Strasbourg/CNRS, France,

    Luis Rivera

  5. Department of Earth and Atmospheric Sciences, Saint Louis University, 3642 Lindell Boulevard, St Louis, Missouri 63108, USA,

    Keith D. Koper

  6. US Geological Survey, NEIC, MS 966 Box 2504, DFC, Denver, Colorado 80225, USA,

    Alexander R. Hutko

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  1. Thorne Lay
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All authors contributed equally to the analysis and preparation of this paper.

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Correspondence to Thorne Lay.

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Supplementary information

Supplementary Information

This file contains Supplementary Methods Applications, Supplementary Figures S1-16 and legends for Supplementary Movies 1 and 2. (PDF 3126 kb)

Supplementary Movie 1

Animation of P wave back-projections from 6 regional networks. (MOV 1735 kb)

Supplementary Movie 2

Animation of the USGS located aftershock sequence. (MOV 4085 kb)

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Lay, T., Ammon, C., Kanamori, H. et al. The 2009 Samoa–Tonga great earthquake triggered doublet. Nature 466, 964–968 (2010). https://doi.org/10.1038/nature09214

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