[dead]

That's just hills in the background.

[Lazamataz]

The wave in the foreground, then, simply doesn't look that large. But, of course, as we know looks are clearly decieving in this case.

[big bad easter bunny]

Look at the top of the mast in each picture, then the mountain is gone in the last, I think that is the wave , not a mountain.

[redheadtoo]

That's just hills in the background.

That "hill" is moving toward the shore. Notice how it is closer to the white boat in the second picture. That big blue thing in the background is the Tsunami wave heading toward landfall.