Abstract

Seismic–tectonic activity and sedimentaryinstability processes can generate submarine landslides thatseriously damage seafloor infrastructures and generate largedestructive tsunamis if the slide volume is high (more than 1km3). Sedimentary instability had resulted in a submarine massfailure (SMF) along the North West Borneo Trough (NWBT).This paper presents numerical simulations for a potentiallandslide tsunami triggered by a SMF in NWBT by acombination of TUNA-LS and TUNA-M2. TUNA-LS simulateslandslide tsunami generation based upon an empiricalformulation for landslide tsunami initialization. TUNA-M2solves the 2-D non-linear shallow water equations for simulatingtsunami propagation, using tsunami initial conditions calculatedby TUNA-LS as input. This landslide tsunami is potentiallydestructive, with source trough maximum wave height of 120 m.The waves in the front propagate forward in the primarydominant slide direction due northeast. Sabah, Brunei andSarawak are located in the direction perpendicular to thisprimary dominant propagation direction. Hence the secondarywaves travel southeast towards Sabah, southwest towardsBrunei and Sarawak. Simulated offshore wave heights at 50 mdepth may reach 15 m to 20 m. Run-up wave heights may exceed45 m to 60 m depending on locations, exposing communities toextreme hazards.