|
 |
 |
| USGS |
| Dust storm in Senegal, Africa. |
|
 |
| Richard Frear, USGS |
| Sand Dunes in Death Valley,
California. |
|
|
1. Which of the images shows sediments
in motion? What is causing it to move?
|
 |
| Peter Kresan, University of Arizona |
| Sand dunes in Algodones,
California. |
|
 |
| USGS |
| Close-up photograph of desert
soil in China. |
|
|
2. What accounts for the absence
of dunes in the image to the right?
|
 |
| Wind Erosion Research Unit, USDA |
| Dunes accumulating
against hay bales in Pratt County, Kansas. |
|
 |
| Wind Erosion Research Unit, USDA |
| Dust blowing over a field in the central plains of North America. |
|
|
3. Why are dunes forming against
the hay bales but not in the open field?
|
 |
| Wind Erosion Research Unit, USDA |
| Irrigated cropland in the central plains of North America. |
|
 |
| Wind Erosion Research Unit, USDA |
| Sand dunes in the
Sahara Desert of Africa. |
|
|
4. Which of the images was taken
in an area with abundant water?
5. Suggest two reasons for the presence
of dunes in Image B but not in Image A.
|
|
|
|
6.
From these images, predict the conditions required for
dune formation.
|
|
