Identification of Slip Distribution M_w 8.1 Biak Earthquake on February 17, 1996

Abstract

On February 17, 1996, at 05:59:30 UTC there was an Mw 8.1 earthquake. Besides, it caused a tsunami. This event occurred in the northern part of the Cendrawasih Bay, where the New Guinea Thrust segment had a relatively low average slip velocity. To obtain a finite fault, waveforms from a tele-station located 30-90 degrees are used. The far-field body wave equation is used and inverted by the Kikuchi-Kanamori algorithm. In addition to obtaining source parameters, this study also aims to determine the value of the rupture velocity that occurs during coseismic events. From this research was found that the rupture velocity (vr) was 2.5 km/s, which occurred at a depth of 13.7 km. The largest value of vector slip is 2.31 m, with an average slip value of 0.922 m. The dimension area of the fault has a size of 272 km × 110 km. The seismic moment obtained is 1.5 × 1021 Nm, which is equivalent to Mw 8.1. This study also found a variance of 0.2844 in the use of the P and SH wave components, which is the smallest variance from the use of the P, P and SH, and SH components in the Kikuchi-Kanamori Program.

Solving the Puzzle of the 1996 Biak, Indonesia Tsunami

“…In the present study, these fault models were used in tsunami simulations to determine whether any of them can explain the tsunami runup distribution. Since Henry and Das (2002) and Arimuko et al (2021) provided no detailed sub-fault parameters, for simplicity, we assumed that their model represented a single fault. Also, we set a depth of 10 km for the fault reported by Tanioka and Okada (1997) because they did not give a depth value in their paper.…”