Quote Originally Posted by Future Esthar
How do you know they didnīt alter?

The one we saw on Esthar donīt produced craters because the Estharians cleverly prevented it using energy fields.
It didn't alter the map because there isn't any noticeable change to the terrain. You've also got no proof that any such energy fields exist, any more than Balamb is Dollet or Deling City is Midgar or whatever.