Figure 3 - Site of former villages on denuded sandbar. There is currently no consensus on the cause of the tsunami. It is difficult to explain why the relatively modest magnitude earthquake resulted in the very large wave heights concentrated over a small area. There would seem to be more causes than the tectonic deformation associated with the earthquake itself. Other mechanisms that have been proposed include submarine slumping, a combination of tectonic and landslide sources, diapiric emplacement of mud volcanoes, and ocean bottom topography.
Research is underway in several countries in an effort to understand the mechanisms involved.
Figure 4 - Map showing reported arrival times of positive waves after the earthquake. The tsunami waves hit a section of the PNG northeastern coast in which population was concentrated in ten villages accommodating approximately 15,000 people. The government reports that at least 2200 persons died as a result of the tsunami, but the exact toll will never be known because pre-tsunami population figures are not available. People reported that the wave took them up, ripped off their clothes and tossed them about. Rescuers found some victims impaled on mangrove stumps, and others with limbs severely cut by metal roofs.