Modelling Considerations for Dynamic Boundary Conditions in Respect to Tsunami Run-Up Simulations from 100 m Depth

Modelling of tsunami in shallow coastal waters involves fast flows which become complex as they reach the shore because of seabed and shore line boundaries, the pickup and deposit of sand, gravel, coral and rocks. This results in dynamic changes in the water/seafloor boundaries and the water/air boundaries. Typically, the seafloor may locally become deeper or shallower, giving rise to sand banks and small islands being removed and/or added. The consequences are further made more complex by reflections from shoreline solid features, deposition, and removal of materials such as sand on land. There may also be resulting complex chaotic waves and cross currents or even large vortices as seen in the Phuket video footage of the 26 December 2004 Indian Ocean Tsunami. Attempts to model such phenomena are describes in order to improve understanding of possible effects of future tsunamis.