Open Access

Coseismic and postseismic crustal deformation after the M w 8 Tokachi-oki earthquake in Japan

  • Shinzaburo Ozawa18Email author,
  • Masaru Kaidzu18,
  • Makoto Murakami18,
  • Tetsuo Imakiire18 and
  • Yuki Hatanaka18
Earth, Planets and Space201456:BF03352530

Received: 9 February 2004

Accepted: 11 June 2004

Published: 24 June 2014


The permanent Global Positioning System (GPS) array in Japan detected coseismic and postseimic deformation of the 2003 Tokachi-oki earthquake (M w 8). We estimate the time evolution of its postseismic slip, together with its coseismic slip distribution. The result shows that the postseismic slip has been occurring mainly in an area adjacent to the coseismic slips, propagating to the northeast and southwest. This suggests that, as of March 6, 2004, the postseismic slip of the strongly coupled area neighboring the coseismic rupture partly released seismic moment, equivalent to an earthquake of M w 7.8.

Key words

Tokachi-oki earthquakecoseismic deformationafterslippostseismic deformation