Tropical rain may have formed Utah’s Great Salt Lake, says Stanford researcher

The Great Salt Lake in Utah is the last remnant of Lake Bonneville, which once covered much of the state. (Photo: karma17/Creative Commons) New research suggests the Great Basin was flooded during the last glacial period by storms moving up from the tropics. By Bjorn Carey Between 20,000 and 14,000 years ago, the deserts in the American Southwest were covered with enormous lakes. How all that water got there has long puzzled Earth scientists, but new work by a group of scientists that includes a Stanford climate researcher could provide an answer. For decades, scientists believed that the 3-kilometer-thick ice sheet that covered much of North America split the jet stream that runs eastward across the northern United States and Canada, redirecting the path of Pacific storms southward over the western states. Over time, these diverted storms were thought to have dumped enough precipitation to create lakes that covered about a quarter of both Nevada and Utah. The largest and best known of these lakes are Lake Bonneville, whose remnant is the Great Salt Lake, and Lake Lahontan in Nevada.