Observation and modeling of the January 2009 west Papua, Indonesia Tsunami

摘要

We modeled a tsunami from the West Papua, Indonesia earthquakes on January 3, 2009 (Mw = 7.7). After the first earthquake, tsunami alerts were issued in Indonesia and Japan. The tsunami was recorded at many stations located in and around the Pacific Ocean. In particular, at Kushimoto on Kii Peninsula, the maximum amplitude was 43 cm, larger than that at Manokwari on New Guinea Island, near the epicenter. The tsunami was recorded on near-shore wave gauges, offshore GPS sensors and deep-sea bottom pressure sensors. We have collected more than 150 records and used 72 stations' data with clear tsunami signals for the tsunami source modeling. We assumed two fault models (single fault and five subfaults) which are located to cover the aftershock area. The estimated average slip on the single fault model (80 9 40 km) is 0.64 m, which yields a seismic moment of 1.02 9 1020 Nm (Mw = 7.3). The observed tsunami waveforms at most stations are well explained by this model.