Why are tsunarmis so bad?

Answer 1

Several reasons. First of all, a tsunami begins with an earthquake. So there is a good possibility that the earthquake will cause damage, especially if it's a large one.

Secondly, even 'small' tsunamis will usually create 10-foot tall waves (slightly above 3 meters) which may not sound like much, but it is - most houses and one-story buildings aren't much taller than that. And the wave is incredibly powerful - the weight of the water, combined with the speed at which the wave travels, can create incredibly destructive force (mass * velocity = energy).

Finally, not only will the wave do a lot of damage to unprotected shorefront properties, the water itself causes its own problems. Flooding is a major concern, water damage to building that weren't already destroyed by the wave, marine life getting washed ashore and dying/decaying - it adds up.

And the kicker - as our global average temperature continues to climb, the planet's ocean levels will rise, which will not only exacerbate the damage done by tsunamis (higher waves), but also the radius where the damage occurs.