How Do We Model Tsunami?

We identify potential tsunami sources, and make an assessment of the magnitude and frequency of tsunami generated by that source. The propagation of a tsunami is then simulated through the open ocean. The behaviour of the tsunami around the coast and as it inundates the coast is then modelled.

We do this by employing the following techniques:

  • Probabilistic and scenario tsunami hazard modelling: identify magnitude and frequency of tsunami sources using geophysical information and historical catalogue. Model earthquake rupture and subsequent propagation through the open ocean to the area of interest to determine extent of inundation. This modelling can be scenario based or probabilistic.
  • Palaeo-tsunami investigation: identify and characterise individual pre-historic tsunami events. This helps to extend the tsunami record by thousands of years, leading to a better understanding of tsunami frequency, magnitude and dynamics and therefore improve the understanding of tsunami hazard. Palaeo-tsunami studies can identify previously unknown areas that could be exposed to tsunami impact in the future.
  • Model validation: Test tsunami hazard models, e.g. can the model simulate the observed tsunami behaviour? Validation examples could be to compare the open ocean simulation to DART buoy measurements from deep water and tide gauge measurements from shallow water. Validation of the inundation model can include comparisons with wave tank experiments and observed inundation extent from historical events. Validation of the numerical procedure can also be undertaken that includes sensitivity and convergence studies.

Topic contact: hazards@ga.gov.au Last updated: July 17, 2013