Particularly arresting was the Al Jazeera video clip below (there's a similar clip in the Guardian), which shows the tsunami in Kamaishi city docks. There's an astonishing amount happening in it.
It was only after I'd watched it four or five times that I realised that the water level in the harbour was rising. At 26 seconds in, the water is several feet below a large Japanese sign beneath the windows on the white building. At 57 seconds in, it's reached the top of the window. So it's risen something like 15 feet in 30 seconds. And already at 26 seconds it looks like it's already 10 feet above ground level.
The same speed is apparent on the elevated roadway, which slopes down towards ground level in the distance. At 30 seconds you can see a couple of vehicles driving up this slope towards the camera. By 53 seconds, that slope has been covered in water. At 57 seconds, it's risen almost to the top of the slope, and white water is visble behind a couple of trucks stopped at the top.
What the hell was any traffic doing on this road anyway, driving along the waterfront? What the hell were the two cars doing driving through puddles of water at ground level underneath the elevated road, visible at 22 seconds? The tsunami took about an hour to get to the east coast of Japan after the earthquake. So why hadn't low-lying coast roads been closed, and traffic directed away from the waterfront?
Did those two drivers survive? There was already quite a lot of water on the road, and it was rising. Chances are that a few hundred yards further on they could have found the water was impassable. And there would have been no escape.
There's really quite a lot of traffic on these roads, it seems. And given the rate at which the water was rising, it seems entirely plausible that dozens of cars and trucks got caught, and never got out. There might have been 100 people drowning in their cars on the streets of Kamaishi by the 57 second mark.
And that doesn't count the pedestrians who were on the streets, or on the ground or first floors of buildings. There could easily have been another 100 of them. Or more. After all, if car and truck drivers were cheerfully driving along the front, and were even standing on the elevated road gawping at it all, then it's very likely that shoppers and shopkeepers and dock workers and boat crews didn't think there was much danger either.
The more I looked at this scene, the more likely it seemed to me that, just in the camera field of vision, a few hundred people could have lost their lives. In the whole of Kamaishi, which has a population of 40,000 or so, maybe 1000 people were caught.
And quite needlessly, it would seem. They had a whole hour to clear the lowest-lying ground. It's not as if they don't know about tsunamis. It's a Japanese word, after all.
But as I write, the death toll in the whole of Japan is set at just 1000. Since Kamaishi is just one town among hundreds all along the eastern Japanese seaboard, the actual death toll looks to me more likely to be more like 100,000.
And then, apart from all the lives lost, there's the damage. Hundreds of thousands of smashed cars and trucks and boats. Tens of thousands of houses swept away. Roads feet deep in mud and detritus. All the drains will be blocked. Most of the power will be out. A lot of people will be homeless. All damage done just by the tsunami, not the earthquake.
See also this for a terrifying 9 minute amateur video.