Y. Tanioka K. Satake S. Yamaki E.L. Geist K. Hirata 2004 <p><span>We estimate the tsunami source area of the 2003 Tokachi-oki earthquake (Mw 8.0) from observed tsunami travel times at 17 Japanese tide gauge stations. The estimated tsunami source area (</span><span class="stix">∼</span><span>&nbsp;1.4 × 10</span>⁴<span>&nbsp;km</span>²<span>) coincides with the western-half of the ocean-bottom deformation area (</span><span class="stix">∼</span><span>2.52 × 10</span>⁴<span>&nbsp;km</span>²<span>) of the 1952 Tokachi-oki earthquake (Mw 8.1), previously inferred from tsunami waveform inversion. This suggests that the 2003 event ruptured only the western-half of the 1952 rupture extent. Geographical distribution of the maximum tsunami heights in 2003 differs significantly from that of the 1952 tsunami, supporting this hypothesis. Analysis of first-peak tsunami travel times indicates that a major uplift of the ocean-bottom occurred approximately 30 km to the NNW of the mainshock epicenter, just above a major asperity inferred from seismic waveform inversion.</span></p> application/pdf 10.1186/BF03353066 en Springer The tsunami source area of the 2003 Tokachi-oki earthquake estimated from tsunami travel times and its relationship to the 1952 Tokachi-oki earthquake article