It's complicated. Tsunami forecasting is a very inexact science and "3m" means "very large".
The average actual height in eastern Japan (Tohoku) was 4-6m, but there were peaks up to 20m in places like Ofunato where the local geography funneled all the water upwards.
I'm surprised so many people don't understand what tsunamis are. It's a "wave" created by a sudden shift in the Earth's crust. Imagine, suddenly, water on each of side of that split is now at different heights and has to equalize. It's much closer to just removing a dam that is holding back water equal in height to the new difference between the sea floors.
Despite the common vernacular calling them "waves" they're really more like really really high tides. You're talking about something that happens over, say, 10-90 minutes, not seconds.
A tsunami is not a "bigger" wave like the ones that crash on the beach every minute. A tsunami is a single wave that crashes and crashes and adds more and more and more water for several minutes non stop, not pausing or pulling back for a single second. It is a sudden flood coming from the sea.
Depends on topography and protections in place. 10 1m waves against a sound 1.5m seawall is no big deal. 1 2m wave against the same seawall could be a problem.
It's complicated. Tsunami forecasting is a very inexact science and "3m" means "very large".
The average actual height in eastern Japan (Tohoku) was 4-6m, but there were peaks up to 20m in places like Ofunato where the local geography funneled all the water upwards.
https://en.wikipedia.org/wiki/2011_T%C5%8Dhoku_earthquake_an...
For perspective, the tsunami that topped the seawall at Fukushima Dai-ichi had a peak height of ~14m.
The seawall was 5.7m.
Is height the only thing that matters? Presumably 1x 2m wave is less impactful than 10 x 1m waves spread 20 seconds apart?
I'm surprised so many people don't understand what tsunamis are. It's a "wave" created by a sudden shift in the Earth's crust. Imagine, suddenly, water on each of side of that split is now at different heights and has to equalize. It's much closer to just removing a dam that is holding back water equal in height to the new difference between the sea floors.
What you get is not a "wave" but a wall of water.
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Despite the common vernacular calling them "waves" they're really more like really really high tides. You're talking about something that happens over, say, 10-90 minutes, not seconds.
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A tsunami is not a "bigger" wave like the ones that crash on the beach every minute. A tsunami is a single wave that crashes and crashes and adds more and more and more water for several minutes non stop, not pausing or pulling back for a single second. It is a sudden flood coming from the sea.
A tsunami is a gigantically long wave. I don’t think what you’re describing describes a tsunami.
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Depends on topography and protections in place. 10 1m waves against a sound 1.5m seawall is no big deal. 1 2m wave against the same seawall could be a problem.
Velocity of wave as well.