Exam 18: Deserts and Winds

Like barchans, the tips of a parabolic dune point downwind.

Refer to the world drylands map (fig.18.2)and the atmospheric circulation diagram (fig.18.3A)to answer the question(s)below. -Which desert is a low-latitude, subtropical desert characterized by high atmospheric pressures and descending air masses (not rain shadow deserts).

What is the normal range of annual precipitation in Canada's Arctic polar deserts?

Deposits of windblown silt are called ________.

What is the angle of repose for dry sand?

Stream channels in dry lands that only carry water in response to infrequent rainfall or snowmelt events are called ________.

________ is the skipping and bouncing transport of sand in blowing wind and running water.

During a typical sandstorm, saltating sand grains reach a maximum height of about ________ above the land surface.

Which one of the following is the best measure of the wetness or dryness of a region?

________ dunes are linear sand ridges at right angles to the prevailing wind direction in coastal areas, with a steady supply of sand.

In North America, loess deposits are found mainly in the dry to semiarid lands of southwestern United States and northern Mexico.

Loess consists mainly of silt-sized particles.

What is the term for a streamlined, wind-sculpted rock ridge oriented parallel to prevailing wind direction?

Desert and steppe lands cover about what percentage of Earth's land area?

________ dunes have their tips facing upwind because they are commonly anchored by vegetation.

Intermittent streams in dry areas of the western United States are called ephemeral.

What is the term for a small depression formed by deflation of a desert floor?

The tips of ________ dunes point upwind and commonly result from persistent, onshore winds in certain coastal areas.

What is the angle of repose for coarse dry sand, as on the slip face of a dune, and is this steep enough that you could use a snowboard there for a swift descent?

What is a short-lived desert stream called?