Others have responded in the negative, but I think it *is* the tsunami. All the water that had just been sucked out went somewhere - is sure wasn't all in the foamy crest of that wave. Undersea topography determines where the water "piles up" and where it does not, and also consider this: If that blue mound is a land mass, it's positioned like a breaker island, which *should* be taking the brunt of the tidal wave.
Actually when you have land mass on either side of a habor shore line, it actually funnels the force of the tsunami toward the beach, intensifying it.