The best example I can bring is Landsat island, a little island 20km off the coast of Labrador, Canada, which was discovered in 1976 by analysing Landsat 1 pictures

Source: Gray, David H. (Summer 2000). "Discovering Rocks Off Labrador: A Photo Essay" (PDF).

Furthermore, I found some posts about this topic, so have a gander at these

Www.reddit.com/r/AskHistorians/comments/2wvf97/how_much_did_maps_have_to_be_altered_once/ - talks a bit about this subject

Www.Reddit.com/r/askscience/comments/1icgyf/are_there_any_places_on_earth_that_were/?

Although not ask historians the are some answers there that have sources and all, do they would pass.