Numerical modelling of tsunami wave to assess the possible impacts along western coasts of India

Abstract

Numerical modelling of tsunami waves has been made for the western coasts of India using TUNAMIN2 code. In this study, the fault parameters are considered from earlier published literatures. Bathymetry data and possible tsunami generation locations have been obtained from the ETOPO2 (Global Relief Model) and General Bathymetric Chart of the Oceans (GEBCO) satellite data. For tsunami run-up the land topography data Shuttle Radar Topographic Mission (SRTM) is used. The present simulation consists of a duration of 6 hours (360 min). Possible arrival times with amplitude at various locations have been estimated. The paper also analyses the changes in the directivity of the generated tsunami waves towards the western coasts of India by changing the dip and strike angles as different scenarios. Time series and height along the different parts of Gujarat coast and hourly travel-time chart of the tsunami waves are also discussed. After the earthquake and initial tsunami wave generation, it reached all the locations along the Gulf of Kachchh (Gujarat) in nearly 2 hrs to 5.30 hrs with amplitudes from 1 to 2.5 m, Mumbai in around 4.45 hrs with amplitude of 2 m, Goa in around 3.08 hrs with amplitude 1 m, Karwar (Karnataka) in around 3.12 hrs and Mangalore in around 3.36 hrs with amplitudes 1 m each. The authenticity of the estimated tsunami phases of the 1945 tsunami genic earthquake along the Makran Subduction Zone (MSZ) are corroborated with the available reports and published literatures.