Sediment slump likely caused 1998 Papua New Guinea tsunami

Abstract

Two major marine surveys off northern Papua New Guinea (PNG) earlier this year now suggest, when survivors' reports are taken into account, that last summer's disastrous tsunami there was caused by a sediment slump 25 km offshore. The slump was probably the result of seabed shaking from an earthquake. Not only was a sediment slump, or submarine landslide, responsible for the tsunami, according to the data, but the magnitude and wave‐height distribution of the tsunami along the coast were the result of focusing by local seabed morphology. The conclusions are based on new off‐shore bathymetry, remote operated vehicle (ROV) dive investigations, the time delay between the source earthquake and when the tsunami struck, computer simulation models, and earthquake aftershock distribution. The most critical evidence is in survivors' accounts of the timing of the tsunami relative to the initially felt earthquake and aftershock [see Davies, 1998a].

Submarine landslides in the Santa Barbara Channel as potential tsunami sources

“…The tsunami modeling is therefore dependent on the geological context and the landslide model. Previous authors have modeled potential tsunami generation in the location of the Goleta slide based on models derived from analyses of the 1998 Papua New Guinea landslide tsunami (Tappin et al, 1999(Tappin et al, , 2001Borrero et al, 2001). In general, landslide tsunami amplitudes can vary over more than six orders of magnitude depending on the geological context and the landslide features Watts, 2004a, b).…”

Submarine landslides at the eastern Sunda margin: observations and tsunami impact assessment

“…That makes the investigation of submarine landslides a necessary step for future tsunami hazard assessment. One of the best studied historical events took place in Papua New Guinea, 1998, where a 4 km³ submarine slump was triggered by a comparatively small earthquake (Tappin et al 1999;Sweet and Silver 2003). The generated tsunami inundated nearby coasts, leading to maximal run-up heights of 15 m (Lynett et al 2003).…”

Landslide tsunami hazard in the Indonesian Sunda Arc

“…Hampton et al, 1996;Yalçiner et al, 2003;Masson et al, 2006). The involvement of submarine mass movements could be proven amongst others for the 1929 Grand Banks tsunami (Heezen and Ewing, 1952;Piper and Aksu, 1987), the Aleutian tsunami of 1946 , the Skagway event in 1994 (Lander, 1995;Kulikov et al, 1996) and the Papua New Guinea tsunami in 1998 (Tappin et al, 1999;Okal, 1999). Volumes of tsunamigenic submarine landslides range between several million m 3 (i.e.…”