Skip to main content

Measuring ground deformations with 1-Hz GPS data: the 2003 Tokachi-oki earthquake (preliminary report)


We analyzed 1-Hz GPS data observed at 14 stations of the GPS Earth Observation Network (GEONET) of the Geographical Survey Institute, Japan, associated with the 2003 M JMA 8.1 Tokachi-oki earthquake, which occurred at the Kurile Trench. The GPS stations are located 70–240 km away from the epicenter. GPS data clearly captured rapid co-seismic ground displacements. At a GPS station 70 km away from the epicenter, coseismic displacements started 15 seconds after the origin time, and after 40 seconds at the stations 240 km away. Observed displacement amplitude exceeded 20 cm at GPS sites 240 km away from the epicenter. Displacement amplitudes attenuate with time and distance from the epicenter, oscillating with periods of 40–60 seconds. We compared the 1-Hz GPS data and displacement seismogram integrated from strong ground motion data, which showed fairly good agreements. In spite of careful screening of 1-Hz GPS data during 30 minutes preceding the main shock, no significant preseismic deformation over 1 cm in the horizontal components was recorded. 30 second sampling GPS data at 14 sites during 20 hours preceding the main shock did not show any significant pre-seismic deformation, either. These results indicate that pre-seismic strain change, if any, was smaller than 0.5–1.0×10−7 before the 2003 Tokachi-oki earthquake.


  1. Boore, D. M., Effect of baseline corrections on displacements and response spectra for several recordings of the 1999 Chi-Chi, Taiwan, earthquake, Bull. Seis. Soc. Am., 91, 1199–1211, 2001.

    Article  Google Scholar 

  2. Boore, D. M., C. D. Stephens, and W. B. Joyner, Comments on baseline correction of digital strong motion data: Examples from the 1999 Hector Mine, California, Earthquake, Bull. Seis. Soc. Am., 92, 1543–1560, 2002.

    Article  Google Scholar 

  3. Geographical Survey Institute, Ground deformation in the 2003 Tokachi Oki earthquake, 101st meeting of Coordinating Committee for Earthquake Prediction, 2003.

  4. Hugentobler, U., S. Schafer, and P. Fridez, Bernese GPS Software Version 4.2., Astronomical Institute University of Berne, 515 pp., 2001.

    Google Scholar 

  5. Irwan, M., F. Kimata, N. Fujii, S. Nakao, H. Watanabe, S. Sakai, M. Ukawa, E. Fujita, and K. Kawai, Rapid ground deformation of the Miyakejima volcano on 26-27 June 2000 detected by kinematic GPS analysis, Earth Planets Space, 55, e13–e16, 2003.

    Article  Google Scholar 

  6. Larson, K., P. Cervelli, M. Lisowski, A. Miklius, P. Segall, and S. Owen, Volcano monitoring using GPS I. Filtering strategies, J. Geophys. Res., 106, 19,453, 2001.

    Article  Google Scholar 

  7. Larson, K., P. Bodin, and J. Gomberg, Using 1-Hz GPS data to measure deformations caused by the Denali Fault earthquake, Science, 300, 2003.

  8. Linde, A. T. and I. S. Sacks, slow earthquakes and great earthquakes along the Nankai trough, Earth and Planetary Science Letters, 202, 265–275, 2002.

    Article  Google Scholar 

  9. Miyazaki, S., T. Sagiya, T. Tada, and Y. Hatanaka, One Hz sampling GPS as an ultra-long-period seismograph, 1997 AGU Fall Meeting, December 8–12, San Francisco, California, 1997.

    Google Scholar 

  10. Mogi, K., Temporal variation of crustal deformation during the days preceding a thrust-type great earthquake—the 1944 Tonankai earthquake of magnitude 8 in Japan, Pure Appl. Geophys., 122, 765–780, 1985.

    Article  Google Scholar 

  11. National Research Institute for Earth Science and Disaster Prevention, The 2003 Tokaichi-oki Earthquake,, 2003.

    Google Scholar 

  12. Yagi, Y., Rupture Process for September 26 2003 Tokachi-oki, Japan, earthquake,, 2003.

    Google Scholar 

  13. Yamanaka, Y. and M. Kikuchi, Source process of the recurrent Tokachioki earthquake on September 26, 2003, inferred from teleseismic body waves, Earth Planets Space, 55, e21–e24, 2003.

    Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Meilano Irwan.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Irwan, M., Kimata, F., Hirahara, K. et al. Measuring ground deformations with 1-Hz GPS data: the 2003 Tokachi-oki earthquake (preliminary report). Earth Planet Sp 56, 389–393 (2004).

Download citation

Key words

  • 2003 Tokachi-oki earthquake
  • 1-Hz GPS measurements
  • coseismic deformation
  • preseismic deformation