Will tsunamis affect California?

Do tsunamis affect volcanic-formed islands differently than bedrock formed islands, like Manhattan?

• Im just spit-balling here, but i know there are different types of rock strata. what im interested in finding out is how a tsunami would affect say, strata formed by volcanic eruptions like Hawaii, as opposed to the bedrock-based strata under Manhattan. Does it affect the underlying water tables? Does it shift the island's position ?

• Answer:

  Different rock strata make no measurable difference. If an island were surrounded by deep water right up to cliffs at the water's edge, that would make a difference. The energy of the shallow, fast moving wave would be reflected the off the rock face. Most islands have a significant shelf, where the wave will slow down and stack up in a manner much like it does on a continental shelf. It is likely that the shelf around an island would be narrower and steeper, so that the stack-up would occur in a shorter fetch of water, possibly resulting in less internal friction loss and more energy delivered on shore, but that effect would be small compared to the overall energy of the tsunami.