In the past, larger lakes existed inside the Deriba caldera. The first such lake stage has been dated to 19,000 years before present when water levels rose above the present-day levels, the second 19,600 - 16,000 years before present when they were higher than currently and the third 14,000 years before present, then above present-day. Similar lake stages have been documented in Trou au Natron in Tibesti, where shifts of the position of the subtropical jet stream and the tropical depressions associated with the jet stream have been invoked as an explanation. These lake stages have left limestone deposits in the caldera, and it is likely that the lakes sometimes overflowed through the eastern caldera rim gap.