According to a statement from Google, made several months ago when this was first discovered, the geometric shapes seen on this image are due to the grid pattern the survey ship sailed in order to take accurate readings of the area.
Other explanations have included the lost city of Atlantis, an undersea Alien base or a top secret research facility accessible only by submarine.
I personally don't know what to say but I don't really believe the explanation of Google Earth, because why is it not showing patterns like this everywere. Although I wouldn't say it is Atlantis either. Maybe a unknow historical city that was submerged by water in the old days.