Special Issue: Special section for the 2003 Tokachi-oki earthquake
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Joint inversion of strong motion and geodetic data for the source process of the 2003 Tokachi-oki, Hokkaido, earthquake
Earth, Planets and Space volume 56, pages 329–334 (2004)
The strong motion and geodetic data were individually inverted for the source process of the 2003 Tokachi-oki, Hokkaido, earthquake with a hypocenter 25 km deep and a fault plane above the subducting Pacific slab. Both the results show a simple slip distribution with a single major asperity, but the strong motion inversion may include a trade-off between slip location and rupture time and the geodetic inversion does not have sufficient resolution for far slips. We then carred out a joint inversion of the two datasets in order to overcome these weaknesses of the single dataset inversions. The resultant slip distribution still retains the simple pattern and has a seismic moment of 2.2 × 1021 N·m (Mw 8.2). The asperity, with a peak slip of 7.1 m, is located in the center of the fault plane 50 km away from the hypocenter in the down-dip direction. The slip rate functions on subfaults around the hypocenter and asperity indicate that the rupture propagated with a supershear speed on the upper part of the fault plane and slowed down to 100–90% of the S-wave velocity on the middle and lower parts. These simple slip patterns and near-supershear rupture may imply the maturity of the Hokkaido subduction zone around the source region.
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An erratum to this article is available at http://dx.doi.org/10.1186/BF03352504.
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Koketsu, K., Hikima, K., Miyazaki, S. et al. Joint inversion of strong motion and geodetic data for the source process of the 2003 Tokachi-oki, Hokkaido, earthquake. Earth Planet Sp 56, 329–334 (2004). https://doi.org/10.1186/BF03353060
- Source process
- joint inversion
- strong motion data
- geodetic data