Nevada Great Basin cavern full of stalagmites studied by MIT researchers.
We know that the American West was once much wetter than it is today; the region is riddled with ancient lake beds and fossilized aquatic creatures. At some point in the last 15,000 years, these inland seas disappeared and turned to desert – but exactly when this happened was not well known.
Until recently: a group of MIT researchers has discovered that the American west must have dried up just about 8,200 years ago – and that it did so relatively rapidly. Read more here.