These two words are often used
interchangeably, but do not mean the same thing. Uncharted means
unmapped. For example, Canada, as recently as 1916 was about 25
percent still uncharted.
Unexplored means a
geographic area where no one has explored or investigated and
published their findings. There are considerable areas of the
jungles in Brazil, Indonesia, and desert areas such as the
Sahara, the Namib desert, central Australia, and desolate cold
areas such as Siberia, northern Canada, Greenland, Antarctica,
remote areas in central Asia, and central Africa that are still
essentially unexplored. As recently as 2011, British researchers
were using Google Earth to look around Africa when they noticed
a patch of forest on and around Mozambique's Mount Mabu that
they never knew existed. It was uncharted and unexplored.