Where and when water is available places a pivotal control on environments – with ancient sediments and fossils explaining how rainfall has changed through time, although researchers now believe climate scientists have read some historical signs about rainfall levels incorrectly.

USC Dornsife researchers studying the history of Utah’s Great Salt Lake identified two brief, deep-lake phases when the water was much fresher than now. Their analysis of core samples spanning the past 240,000 years shows that the most recent freshwater phase, which formed Lake Bonneville, lasted longer and was fresher than the earlier Little Valley lake phase. The researchers found that both lakes shrank and became salty as the regional climate warmed and dried, offering possible insights into Great Salt Lake’s future in the face of climate change.