NUMERICAL-SIMULATION OF THE 1992 FLORES TSUNAMI, INTERPRETATION OF TSUNAMI PHENOMENA IN NORTHEASTERN FLORES ISLAND AND DAMAGE AT BABI ISLAND

Numerical analysis of the 1999 Flores Island, Indonesia earthquake tsu nami is carried out with the composite fault model consisting of two d ifferent slip values. Computed results show good agreement with the me asured runup heights in the northeastern part of Flores Island, except for those in the southern shore of Hading Bay and at Riangkroko. The landslides in the southern part of Hading Bay could generate local tsu namis of more than 10 m. The circular-are slip model proposed in this study for wave generation due to landslides shows better results than the subsidence model, It is, however. difficult to reproduce the tsuna mi runup height of 26.2 m at Riangkroko, which was extraordinarily hig h compared to other places. The wave propagation process on a sea bott om with a steep slope, as well as landslides, may be the cause of the amplification of tsunami at Riangkroko. The simulation model demonstra tes that the reflected wave along the northeastern shore of Flores Isl and, accompanying a high hydraulic pressure, could be the main cause o f severe damage in the southern coast of Babi island.