35 Numerical Modeling of Tsunami Waves Associated With Worst Earthquake Scenarios of the Makran Subduction Zone in the Jask Port, Iran Akbarpour Jannat, MahmoudReza *1 ; Rastgoftar, Ehsan 1 Iranian National Institute for Oceanography and Atmospheric Science (INIOAS), Tehran, IR Iran Received: June 2015 Accepted: November 2015 © 2015 Journal of the Persian Gulf. All rights reserved. Abstract The recent studies show that the past researches may have significantly underestimated earthquake and tsunami hazard in the Makran Subduction Zone (MSZ) and this region is potentially capable of producing major earthquakes. In this study, the worst case possible earthquake scenarios of the MSZ are simulated using fully nonlinear boussinesq model to investigate tsunami hazards on the Jask Port, one of the most important southern coastal areas of Iran. The 9.1Mw and 8.7Mw earthquakes which respectively, represent the rupture of about full and half length of the MSZ plate boundary, have been considered in the modeling. The global and local numerical simulation were conducted based on 1-minute and 3-arc sec resolution bathymetry data, respectively, in order to capture tsunami generation, propagation and inundation at the Jask Port. Results show the water subsidence is firstly obsereved along the Jask Port coastlines just after the earthquake occurrence, which can alert residents as a natural warning sign. Model results also reveal that due to the 9.1Mw earthquake and the 8.7Mw western Makran earthquake, the most coastal areas around the Jask Port are inundated by tsunami waves. However, the tsunami run-up is not observed when the 8.7Mw earthquake occurs at the eastern segment of the MSZ because the tsunami waves almost propagate in the north-south direction, perpendicular to the Makran fault and it causes a little effect of the tsunami attack on the western coast of Makran. Therefore, the most crucial factor that determines the tsunami risk at the Jask Port is the location of earthquake focal points in the Makran region. Keywords: Makran Subduction Zone, Tsunami, Jask Port, Numerical model, Inundation 1. Introduction Following the catastrophic Indian Ocean tsunami in December of 2004, which resulted in fulmination to more than 225,000 humans live and homelessness of more than one million people (Geist, Titov et al. 2006) and 2011 Japan tsunami which caused indescribable damage and casualties, paying more serious attention to this phenomenon and to assessing the vulnerability of different coasts around the world, especially for marginal Indian Ocean countries like Iran, is required. Definitely, Makran tsunami in 1945 and powerful tsunami of Indonesia in 2004 are not the first or the last such occurrences in the region. Indeed, the behaviour of three Eurasian, Indian and Journal of the Persian Gulf (Marine Science)/Vol. 6/No. 22/December 2015/13/35-48 * Email: akbarpour@inio.ac.ir