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USGS CMG InfoBank: Blowouts and Oasis

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Comment: 15:11 - 16:09 (00:58)
Source: Annenberg/CPB Resources - Earth Revealed - 22. Wind, Dust and Deserts
Keywords: "Richard Hazlett", desert, wind, dune, blowout, stream, Sahara, "Earth's surface", vegetation, soil, sediment, "water table", oasis

Our transcription: The same winds that build up dunes may also hollow out depressions in the land surface.
These dish shaped hollows are called "blowouts."
Sometimes wind can be channeled in narrow streams.
In parts of the Sahara Desert this is happening, for example, between long rows of parallel dunes.
Where this wind is concentrated against the Earth's surface, it can blow away vegetation and through time, bit by bit, carry away the loose soil and sediment present at the Earth's surface as well.
Under certain extreme circumstances, so much material may be removed that the top of the water table is exposed, and this provides for creation of an oasis.
These aren't common in most parts of the world, but do occur in some of the larger deserts.

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Page Last Modified: Thu Oct 31 04:27:41 PDT 2013  (chd)