fundamentally different processing than normal surfing waves. a surfing wave or most waves that you sea at the beach are generated by wind. the higher the wind, the bigger the waves. but a tsunami is generated by d displacement coming up from the sea floor. the key is it happens over many hundreds or thousands of square kilometers. so suddenly you have water that's gone up a little bit in the ocean and it's got to go somewhere. it can pass under your boat if you're out in the open ocean and you want even feel it. but once it hits the shore and it shows up, you've got basically a meter of water that extends back 100 miles. that meter of water suddenly piles up on the shore. that's when you see the pictures of tsunamis, they don't look like a wave as much as a river that comes in on the coastline.