In Chad, sand helps send nutrients all the way to the Amazon.
In the Bodélé Depression, sand grains blow across the bed of a dried-up lake. As they bounce over the surface, they knock much finer particles loose from the sediment.
That fine dust can be lifted high into the atmosphere and travel thousands of kilometres across the Atlantic. It carries nutrients including phosphorus, helping replace some of what the rainforest loses through heavy rainfall.
The sand grains do not make the whole journey. But they help set it in motion.
