A big wall in the middle of the Atlantic Ocean might work. We could raise it when that Canary Island volcano blows and half the island falls into the sea. On the other hand, blowing the island in half by stages might work, too, but the inhabitants might disagree.
I read an article some time ago that mentioned a large landslide off the continental shelf could also generate a tsunami. If a tsunami doesn't get you within a thosusand years, a hurricane probably will.