What is a moraine?

A moraine is a mound, ridge, or any other distinct accumulation of unsorted, unstratified material or drift, deposited chiefly by direct action of glacier ice.

What is a hoodoo?

A hoodoo is a fanciful name for a grotesque rock pinnacle or pedestal, usually of sandstone, that is the result of weathering in a semi-arid region. An outstanding example of a hoodoo occurs in the Wasatch Formation at Bryce Canyon, Utah.

What are sand dunes and how are they formed?

Mounds of wind-blown sand in deserts and coastal areas are called dunes. Winds transport grains of sand until it accumulates around obstacles to form ridges and mounds. Wind direction, the type of sand, and the amount of vegetation determine the type of dune. Dunes are named either for their shape (e.g., star dunes and parabolic dunes) or according to their alignment with the wind (e.g., longitudinal dunes and transverse dunes).

Which are the world’s largest deserts?

Deserts are distinguished by two general characteristics. First, desert areas receive less than ten inches of precipitation per year. Second, due to the extreme dryness, there is little plant or animal life in most deserts. Many deserts form a band north and south of the equator at about 20 degrees latitude because moisture-bearing winds do not release their rain over these areas. As the moisture-bearing winds from the higher latitudes approach the equator, their temperatures increase and they rise higher and higher in the atmosphere. When the winds arrive over the equatorial areas and come in contact with the colder parts of Earth’s atmosphere, they cool down and release all their water to create the tropical rain forests near the equator. However, other parts of the world, such as Antarctica, are also desert regions. The average annual precipitation in Antarctica is less than ten inches per year.

The Sahara Desert, the world’s largest, is three times the size of the Mediterranean Sea. In the United States, the largest desert is the Mojave Desert in Southern California with an area of 15,000 square miles (38,900 square kilometers).

*Includes the Simpson, the Great Victoria, the Sturt Stony, the Gibson, the Great Sandy, and the Tanami.


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