The trees and plants in the Amazon rainforest rely on nutrient-rich dust from a single valley in the Sahara desert for sustenance, researchers have discovered.
快猫短视频s know that millions of tonnes of mineral dust are blown from the Sahara desert to the Amazon basin each year. The dust helps keep the Brazilian rainforest soils fertile.
Now, researchers have found that 56% of this dust comes from one place: the Bod茅l茅 depression in Chad, Africa. They also showed that three times more dust than previously thought is transported each year from the Sahara to the Amazon 鈥� over 40 million tonnes.
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The team, led by Ilan Koren at the Weizmann Institute in Israel, used satellite and geological data to track the 鈥渄ust parcel鈥� across the Atlantic ocean. Watch the dust鈥檚 progress as it begins its journey in this (5MB, avi format).
The Bod茅l茅 valley is 200 times smaller than the Amazon basin, and forms only 0.2% of the Sahara itself. The reason the valley supplies so much dust is its location between two mountain ridges. It forms a funnel that accelerates the flow of air, not unlike a wind tunnel, allowing more dust to be carried. In winter, the valley produces an average of 700,000 tonnes of dust per day.
Journal reference: Environmental Research Letters (DOI: 10.1088/1748-9326/1/1/014005)
