Open AccessNumerical modelling of tsunami generation and propagation from submarine slumps: the 1998 Papua New Guinea event
Author(s) -
Heinrich PH.,
Piatanesi A.,
Hébert H.
Publication year - 2001
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2001.00336.x
Subject(s) - geology , landslide , submarine landslide , shallow water equations , seismology , waves and shallow water , new guinea , submarine , oceanography , ethnology , history
Summary Deep and large submarine slumps may generate tsunamis as disastrous as tsunamis of tectonic origin. Such a landslide is likely to be the origin of the 1998 July 17 tsunami of Papua New Guinea, the deadliest tsunami in the last 50 years. Water waves devastated a 20 km stretch of coastline, wiping out three villages and killing more than 2200 people. A numerical model has been developed to study the efficiency of deep slumps in producing tsunamis and has been applied to the Papua New Guinea event. The landslide is treated as the flow of a homogeneous gravity‐driven continuum governed by a rheological law. Water waves are generated by sea‐bottom displacements induced by the landslide. The shallow‐water approximation is adopted for both the landslide and the associated water waves. The resulting differential equations are solved by a finite difference method based on shock‐capturing. The shallow‐water hypothesis is tested by comparison with a model solving Navier–Stokes equations for a mixture of water and sediments. Sensitivity tests carried out for a 2‐D simplified geometry show that the water surface profile depends strongly on the constitutive law of the landslide. The 1998 event is simulated numerically by the shallow‐water model, testing different friction laws. The observed inundation height distribution is well reproduced by the model for a volume of 4 km 3 , with its top located at a water depth of 550 m, and sliding with a Coulomb‐type friction law over a distance of 5 km.