Japanese Tsunami
This CBS video missed getting shown on every news program back when the Japanese tsunami was the news. I find it very compelling because it so clearly illustrates the nature of a tsunami. Rather than a the popular image of a towering, monster wave that crashes ashore and quickly dissipates its energy, a tsunami expresses itself as a temporary change in sea level that pours the ocean ashore for a sustained period of time. This video shows it exactly like that. The water level in the bay out beyond the row of buildings along the shoreline rises inexorably to a new height more than two stories higher than normal and the water pours ashore through any opening it can find ... or make.
Focus on the big pinkish cinder block building that is the center of attention at the opening seconds of the video. That five story building has a two story extension that makes an excellent gauge of water level.
Keep going back to that as the video progresses.
At first, the water pours around the side of the pink building and down the street. Next, it rises to the point that it breaks into the seaward side of the building through doors and windows and starts to flow through the first floor. Soon the entire contents of that room is being swept out the back door and windows. Quickly, the water level is so high that it has fully engulfed the first floor and then starts flowing out of second story windows which look like waterfalls. Finally, the second story windows are jetting water from floor to ceiling. Buildings down the waterfront look just the same with rivers of water pouring out of them. Toward the end of the video, the water level appears to reach equilibrium just under the roof level of the two story extension. The water stops being a raging river and just holds at that depth. Debris actually swirls gently around in the new two story deep pool behind the building, actually drifting back towards the building. I imaging that a damaging outflow happened next, with water raging back toward the sea, although the video stops and did not record it.
I have watched this video several times and although horrifying, it is a rather ideal depiction of tsunami behavior.
