Numerical modelling of tsunami in the Makran Subduction Zone – A case study on the 1945 event

ABSTRACT Tsunamis cause significant loss of life and damage to properties, ecosystems and marine structures and facilities. Tsunami modelling results are used for deriving robust design conditions for coastal and marine structures and facilities. The results are also used for emergency planning and decision-making to estimate the potential loss of life, damage to properties and marine facilities and to develop rescue and mitigation measures and plan clean-up operations. Royal HaskoningDHV (RHDHV) has set up a regional tidal hydrodynamic model covering the Northern Arabian Sea to provide data to address the above issues. The 1945 earthquake in the Makran Subduction Zone generated a tsunami along the coastlines of Iran and Pakistan killing as many as 4,000 people. Furthermore, the tsunami caused catastrophic damage to properties and other coastal facilities. The tsunami modelling in the present study was carried out for this 1945 event. The MIKE21 Flow Model FM of DHI was used to simulate this tsunami event and sample results from the modelling are presented in this paper for illustration purposes. Structural design considerations and tsunami risk reduction measures are also discussed. The model could be used to simulate any tsunami generated within the Arabian Sea. The methodology described in this paper for modelling the 1945 tsunami in the Makran Subduction Zone could also be applied to simulate this type of events at other sites around the world.