Short of relocating the island by several hundred miles or putting another island in the way, you can't.
yes, if we build some type of wall to prevent a tsunami from hitting land
It is highly Possibility that a tsunami not if but when it will happen and could take out the east coast from maine to Florida the chances in our life time is 1 in 1000
It's not likely for tsunami's to continue hitting Japan.
You can not prevent an earthquake and tsunami like you can prevent getting sick before you get sick.
that depends on where the tsunami is hitting the one in December 2004 costed billions
you can't stop or prevent a tsunami. You can go to a higher ground to get away from it.
no
It doesn't
yes
No. A tsunami is a natural event thankfully mankind can't control nature.
No. China was essentially shielded from the tsunami by the Japanese island.
Unless you know how to tie tectonic plates together so they can't move about or you know how to prevent other geological activity, the answer is no: You cannot prevent a tsunami. However, you can prevent a tsunami from completely destroying a human population by giving people a chance to run away from the tsunami, given prior warning. I'm sure there is some kind of tsunami detector, probably resembling a seismometer.