It's surprising just how much of our regular vocabulary is outdated or based on bad information. "Tidal waves" (as we usually use the phrase) have nothing to do with the tides. They are caused by a disturbance of the seafloor that causes a part of the ocean surface to rise or fall. They can also be caused by avalanches that drop into a sea or shore, displacing a huge amount of water. As time goes on, we seem to be retiring "tidal wave" in favor of the Japanese word "tsunami". But "tsunami" simply means "harbor wave" ... which also fails to describe the actual thing. We've seen a lot of video in recent years showing these massive waves striking places that are not harbors. Historically, it's true that they did enormous damage to Japanese harbors. The word "tsunami" is still outdated and misleading. There's really no good word for these events. They're not really just waves, either. They are vast