[SSS13-P14] Rupture process of the 1979 Tumaco, Colombia, earthquake and rupture characteristics along the Ecuador-Colombia subduction zone
Keywords:1979 Tumaco earthquake, rupture process, Colombia
We inverted teleseismic P-waves at WWSSN stations to investigate the rupture process of the 1979 Tumaco earthquake. We calculated Green’s functions using the method of Kikuchi and Kanamori [BSSA, 1991] and applied the waveform inversion scheme of Kikuchi et al. [EPS, 2003] to image the spatio-temporal slip distribution. Our inversion results indicated that the large slip of the 1979 event occurred in the northeastern part of the source region. The average plate coupling ratio in the 1979 earthquake source region was estimated to be only 30 % [White et al. EPSL, 2003]. From this coupling ratio and the average slip of 2.4 m in our slip model, the recurrence interval of the 1979 earthquake was estimated to be 174 years. This suggests that the 1906 Ecuador-Colombia earthquake did not rupture the source region of the 1979 Tumaco earthquake. This interpretation is consistent with that the tsunami source model of the 1906 event proposed by Yoshimoto and Kumagai [AGU fall meeting, 2016].