Failure of a massive earthquake-induced landslide dam in Papua New Guinea

In many areas of the world, landslides dams are both interesting natural phenomena and significant hazards. A few of the these natural blockages attain heights that rival or exceed those of the largest manmade dams. A landslide dam in its natural state differs from a constructed embankment dam in that it is composed of a heterogeneous mass of poorly consolidated earth debris and has no channeled spillway or other protected outlet for its impoundment. Having no outlet, landslide dams upon overtopping very commonly fail by breaching due to erosion by the overflowing stream. Some of the world's largest and most devastating floods have occurred because of the failure of large landslide dams (Schuster and Costa, 1986).

This article discusses the recent occurrence of a large earthquake-induced landslide that dammed the Bairaman River in the interior of the island of New Britian, Papua New Guinea, and the subsequent overtopping and failure of this landslide dam.