Japan earthquake sparks tsunami scare | Hacker News Reader

Japan earthquake sparks tsunami scare

bbc.co.uk

41 pointsdendory11 comments

I was sitting in my office and coding when the earthquake hit. When people realized it wasn't a small one, everyone just started rushing outside of the building. I thought it wasn't the smartest thing to do since many buildings in Tokyo have lots of glass windows and panels which could literally decapitate you if they hit you... and since virtually all buildings here are built to be earthquake proof, you'd probably be much safer hiding under a desk in your office than going outside and exposing yourself to all the falling debris. Oh well...

The tsunami warning has been lifted again, see http://www.jma.go.jp/en/tsunami/

When measuring waves, is it from top to low, or from middle to top?

My assumption is that the water level represents the center of an oscillating waveform, so it is "top to low" in the sense that it goes from the top of the wave to the "low" representing the normal water level, and it is "middle to top" in the sense that it goes from the (middle) inflection point to the maxima. For the former, note that oscillations may cause a lower amplitude less than the normal water level, but it may look more shallow due to the different diffusion of water relative to air.

Is a 1m wave really something to be concerned about? The ones last year were up to 40.5m tall! In comparison this one doesn't really seem to be that significant but I'm keen to be corrected.

A 1 meter wave can deliver a lot of power but it's probably not really something that will cause much damage in a place like Japan. Keep in mind that the geography of the land will affect the incoming wave. Some geographic features can focus or disperse waves to be larger or smaller. The problem is that you don't really know if it will be 1m or 10m until it is too late.

Our startup (MakeLeaps) is located in Tokyo and this one shook our building enough that one of our support staff who was on the phone with a user asked them if she could call back so she could crawl under the desk. :-) He was far enough away that he couldn't feel it but he was also pretty understanding.

This was one of the first earthquakes in a while that really got my attention. When I saw it was an M7.5 in the same area as the one from 3/11 I thought the tsunami was going to keep getting worse.

Second report of a 1-meter wave hitting ground: https://twitter.com/japantimes/status/276976633565548546

1st wave ended up being 20cm: https://twitter.com/japantimes/status/276975852716167169

All good here in Sangenjyaya. Pretty long one (or two?) though

Hey minikomi,

is there any site you know that tracks how the situation is at Fukushima, like how many of the 204 (?) rods / fuel units have been moved to another nuclear power plant?

Hey mate I guess you could check tepco's official reports, as far as you trust them. They are written very formally and translate quite well in google translate if you copy & paste them over. http://www.tepco.co.jp/nu/index-j.html

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