Would the floating ice and dense cold water slow down the speed of a tsunami at all?
Its a good thought in theory, but I dont think it has an validity. The creation of a tsunami is completely from a physical point of view and that means that it has to do with the transfer of energy through wave action. I don’t see ice cover having enough of an effect to dampen a wave. If you have ever heard stories about tsunamis you probably know that if you are in deep water, the tsunami may be a wave that is 1 foot higher than the rest, meaning you wont even notice it…..the tsunamis become deadly when they reach shallower water and begin to slow down and several waves pile up on top of one another and begin to grow in size. So by just having ice cover there I do not foresee it as stopping that pile up of the water…in fact I could imagine it might make it worse…..