How could I tell? I am Chilean, and I know about earthquakes. We had a major earthquake last year, and even today the land shake… Because of that, I know mortality in earthquakes can be controlled by following building standards. However, our knowledge about tsunami prevention is small.
i think the procedure, if you are in a tsunami zone, is to start running for the hills as soon as the ground stops shaking. those that died because of the quake may not have been noticed before the tsunami.
You run if you can. Japan seems to have a very flat coast, so running away from a tsunami would be very difficult. In the case of my country, almost everywhere you have hills right beside the beaches, so there is more chance to escape.
One of the newspaper reports I read soon after the disaster said that most of the houses along the coast are built of wood so as to be earthquake-resistant, but of course got turned to matchwood by the wave.
I read that even in Sendai, right by the epicenter, few if any buildings collapsed. I had the same question as the OP and reached the conclusion others have (guessed at/reached) – the majority of people probably died in the tsunami.
There were very few deaths caused by the quake itself, as far as I can tell. Maybe in the order of hundreds. The tsunami came very quickly - a matter of 30 minutes or so for most areas, some quicker. You can see from the above link that what started as water spilling over and running down the street rapidly became a massive sea surge that was impossible to resist.
The awful, sad thing is that only half the bodies have so far been recovered, and that number is not going to rise significantly now. If a building can be swished away in a moment, a fragile human body is just nothing. There was a tremendous backrush too, where everything was sucked back out to sea, and this was repeated four or five times.
Last week my husband had to take a guy to identify his brother that they’d found. He (husband) was worried that the man would be very upset but he said that on the contrary, he felt that he was one of the lucky ones - who could see with his own eyes and actually know the fate of his loved one…
from the banda aceh experience and this more recent disaster, mitigation of damage and casualties from tsunami depend on the following:
identification of tsunami-prone shores and the accompanying modifications to land use, build-up and settlements
disaster preparedness by the potential affected municipalities (it’s a lot simpler than you think, see #3)
a steady international earthquake detection and warning system (you already have that) and quick information dissemination to the municipalities. a simple tsunami horn going off 30 minutes before the wave hits will save more than 50% of potential fatalities.
sorry, mistake. and you got me worried there for a moment. the 30-minute-warning-to-save-50%-potential-casualties raises a lot a eyebrows (did for us in geology.) i can think of banda aceh itself and sendai as examples of how an estimate like this could go awry. in both, a two-hour warning might be more correct.