Tsunamis are a geo-hazard that have a high potential to devastate majority of infrastructure in their path. Considering the threat from possible tsunami around the Australian coast, CSIRO Australia, under the Wealth from Ocean Flagship program, initiated studies on tsunami induced hazards to the submarine infrastructure along the northwest Australian coast. This thesis is part of the research work initiated by CSIRO Australia. Experimental and numerical model studies are carried out at UQ to understand the tsunami effects on the seabed especially continental slope and continental shelf. Solitary waves are considered to represent the leading waves of a tsunami. Breaking and non-breaking solitary waves over smooth and rough beds (d50=0.2mm) were generated in the laboratory and the corresponding shear stresses were measured using a Shear Plate apparatus. A physical model was set up in the laboratory that represented the deep horizontal ocean floor, inclined continental slope and the shallow horizontal continental shelf. Measurements of bed shear stress, surface elevation and flow velocities were carried out. Periodic waves were also generated and the bed shear stresses measured over a horizontal bed were found to be comparable with the earlier studies and theoretical estimates. The total force (sum of bed shear stress and pressure gradient force) measured using the shear plate is important in determining the stability of submarine sediment and in sheet flow regimes. The bed shear stresses generated by breaking and non-breaking solitary waves were in laminar and transitional flow regimes (~104

The study by JayaKumar, S., National Institute of Oceanography, Goa, India was part of Endeavour International Postgraduate Research Scholarships, Govt. of Australia CSIRO-Australia - Wealth from Ocean Flagship Program..