Your question is a little vague, and deals with events that are less than 20 years old. Because of the rules of this subreddit the mods may choose to remove the topic, but I'm not sure.

I don't have any knowledge deeper than a wikipedia page about expeditions in the early 1900's. However, I was fortunate to attend a talk given by a current "explorer" named Stefan Kröpelin; he does work on climate science and geology at the University of Cologne. He leads teams of scientists and archaeologists on expeditions to relatively (or completely) unexplored regions of the Sahara Desert.
Nature.com has a good profile of him here. The talk I attended is available through Fora TV in audio for free here. You can watch the video for a subscription fee here - I strongly recommend watching the video: the images and data he showed was really interesting.