Seeing the most heavily hit areas was especially shocking in the first 2-3 days. After a while though, you can start seeing clues in terms of how enormous the tsunami was:

The first footprint was “Missing Homes”, ie- nothing remaining but concrete foundations:There were some towns like Minamisanriku and Ritzukentaka that were bare for miles in every direction…At first sight, you dont think much of the wood and what it is, but in reality, the wood piles were what was left of the houses….…the tsnumai pulverized most homes to splinters….If it was a well built wooden home, it would stay together, just get tossed around like a toy…Occasionally, we would see a very well built concrete building consisting of many stories. Broken windows indicate the minimum Tsunami height, where as unbroken windows indicate what was never covered….Such was the case with Minamiranriku City Hall. Word is that the Mayor survived by getting to the roof and hanging on for dear life as the wave came up to waist high on him….Some buildings were well over 40-50 feel tall and showed damage. There are more pics I have from other areas with even taller destruction lines, but I couldn’t find them…ill have to dig…Another way to measure the height of the wave is the debris line. If it is covered in debris, it is a safe assumption the wave was at least that high at one point. It is more impressive on high mountains because you can see definitively where it stops…I recall seeing one debris line that was a good 90+ feet tall. Very common to see cars on buildings….…and sometimes buildings on buildings