Sunday, July 21, 2013

Factoid of the day

NASA has a photo of a dust plume blowing across the Red Sea. (photo taken June22).

Much closer to the camera—but still more than 550 kilometers (340 miles) from the ISS—is a dust plume surging out over the Red Sea and reaching most of the way to Saudi Arabia. The point source of this plume is the delta of the southern Egyptian river Khor Baraka. Astronaut images have shown that this delta is a common source for dust plumes, mainly because it is a relatively large area of exposed, loose sand and clay that can be easily lofted into the air. The river also cuts a narrow valley through a high range of hills that channels the wind, making it blow faster.
Uh, a "delta" in Southern Egypte?

Actually, a wadi in the Sudan that usually fills with water in July and August, allowing local farmers to grow Millet.




Khor Baraka and its tributaries are seasonal streams which flow between July and September. The rich alluvial soils provide the best medium of growth for millet and the forest resources for which it is well known. There are major agro-pastoral settlements along Khor Baraka which partly depend on millet farming. During the drought of 1984-85, Khor Baraka was able to support almost double its normal population.

more HERE.

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