Does the viscosity of the water affect the tsunami?
No. The viscosity of water is a very small factor. In some problems you need to take viscosity of account, but tsunamis have such a large scale that viscosity plays a minor role. If we are talking about very small waves on the surface of the water, like capillary waves, or waves caused by wind on the water; those waves you need to take viscosity into account, but not with tsunami waves. It’s a good question.
