Question

Deserts: (a) are found in the low, middle, and high latitudes; (b) receive inadequate 1. rainfall; (c) are mostly or completely devoid of vegetation; (d) are characterized by internal drainage; (e) ALL of these. In a desert region, bed load transport is mainly by: (a) saltation; (b) deflation; 2. (c) abrasion; (d) precipitation; (e) suspension. The term for wind-blown silt is: (a) loess; (b) colluvium; (c) alluvium; (d) lopsoil; 3. (e) caliche. The term used to describe large, mid-latitude deserts far from the ocean, such as the 4. Gobi or Takla Makan deserts, is a (b) continental; (c) coastal; (d) subtropical; (e) polar... desert: (a) rainshadow; Earth's subtropical deserts are controlled by the presence of the 5. semi-permanent pressure belts: (a) polar low; (b) subpolar low; (c) subtropical high; (d) polar high; (e) equatorial low. The term for a western desert, that forms opposite a cool, tropical ocean water mass, desert:: (a) rainshadow; 6. such as the California or Canaries currents, is a (b) continental; (c) coastal; (d) subtropical; (e) polar. A desert that lies on the lee side of a mountain range that blocks moisture-laden desert: (a) coastal; (b) rainshadow; (c) subtropical; 7. prevailing winds is a (d) continental; (e) polar. Which of these dunes, among the tallest in the world, consisting of pyramid shaped peaks of sand, develop where the wind direction is variable? (a) barchan; (b) star; (c) longitudinal; (d) transverse; (e) parabolic. 8. Outside of desert regions, dome of the tallest dunes in the world are in: (a) the tropical 9. rainforest; (b) coastal areas; (c) polar tundra; (d) ice shelves; (e) mid-latitude forest areas. The main agent of erosion in deserts is: (a) glaciers; (b) wind; (c) waves; (d) running 10. water; (e) mass wasting. A flat-topped erosional; remnant of a plateau that has cliffs on all sides, and has a 11 surface area greater than one square mile is called a;an: (a) bajada; (b) bolson (c) mesa; (d) hogback; (e) buttes. Coalescing alluvial fans form alan: (a) butte; (b) mesa; (c) playa; (d) inselberg: 12. (e) bajada. A crescent-shaped dune whose tips point downwind is a (b) transverse; (c) parabolid; (d) barchan; (e) longitudinal dune: (a) star 13.

Answer 1

1. Deserts are found in the low, middle, and high latitudes, e.g. the Sahara Desert is a low-latitude desert, the Gobi Desert is a mid-latitude desert, Antarctica is a high latitude desert. Deserts receive inadequate rainfall throughout the year, as a result of which it is commonly devoid of vegetation. Deserts are characterized by internal drainage as the water from the streams in dry regions is not able to reach the sea. So all the options, ie. a, b, c, d are correct, thus the correct option is (e).

2. In a desert region, bedload transport is mainly by saltation that refers to the movement on and off the surface due to the blowing of winds. Deflation, abrasion, and suspension are erosional processes and do not contribute to the transportation of bottom sediments or the bedload. Precipitation causes deposition and lithification of sediments. So options b, c, d, e are incorrect. Thus the correct option is (a).

3. The term for wind-blown silt is loess which is an example of an aeolian deposit. Colluvium is a deposit formed on sloped surfaces due to creep. Alluvium is a deposit formed due to the erosion of sediments by water. Caliche is a rock formed due to carbonate deposition in the sand and silt-sized sediments in the upper soil horizons. Topsoil is the soil layer rich in organic matter. So options b, c, d, e are incorrect. Thus the correct option is (a).

4. Mid-latitude desert such as Gobi Desert is an example of continental desert as such deserts are not located on the leeward slope of mountains and are away far away from the ocean, the subtropics and polar regions. So options a, c, d, e are incorrect. Thus the correct option is (b).

5. Subtropical deserts are controlled by the presence of high-pressure belts over the subtropics that exists due to excess energy over tropics and lack of energy over poles. The general circulation in the atmosphere creates a zone of high pressure due to energy imbalances between equator and pole. So polar or equatorial pressure systems do not directly contribute to the formation of deserts in the subtropics, thus options a, b, d, e are incorrect. Thus option (c) is correct.