If Atlas is as tall as Cronos, than he gotta be 1,500 ft tall (like the sears tower 1450 ft, 442 meters, according to Chris O'Neill)
In the Trivia of the Atlas page it says that the Temple of Pandora must have been created after Chains of Olympus. However, other wiki pages state that the Temple was built 2500 years before Kratos entered the Temple. My suggestion is the theory that the bolder on the statue of Atlas and on the carvings does not represent Earth because there is no land nor water shown on them. The bolder may simply represent Atlas' strength as he was known to be the strongest of the Titans.