a tsunami occurring when a tectonic plate ruptures, but there are other events that can cause a tsunami - collapsing icebergs can cause them also. There's no doubt the climate has changed and the planet is warming up with huge glaciers falling off Greenland this year. Beside the fact they can collide into land areas - we find another threat - the glacial tsunami. This occurs with the capsizing of giant masses of ice that result from calving or splitting off from a glacier vary in shape and size. If their height is larger than their width, they can be unstable following break off and roll over, potentially creating a giant wave.