Read the following text about deserts.

Deserts

http://en.wikipedia.org/wiki/Desert

A desert is a landscape or region that receives very little precipitation. Deserts can be defined as areas that receive an average annual precipitation of less than 250 mm or as areas in which more water is lost than falls as precipitation. Deserts are part of a wider classification of regions that, on an average annual basis, have a moisture deficit (i.e. they can potentially lose more than is received).

Deserts take up one-third of the Earth's land surface. They usually have a large diurnal and seasonal temperature range, with high daytime temperatures (in summer up to 45 °C), and low night-time temperatures (in winter down to 0 °C) due to extremely low humidity. Water acts to trap infrared radiation from both the sun and the ground, and dry desert air is incapable of blocking sunlight during the day or trapping heat during the night. Thus during daylight most of the sun's heat reaches the ground. As soon as the sun sets, the desert cools quickly by radiating its heat into space.

Many deserts are formed by rain shadows, mountains blocking the path of precipitation to the desert. Deserts are often composed of sand and rocky surfaces. Sand dunes called ergs and stony surfaces called hamada surfaces compose a minority of desert surfaces. Exposures of rocky terrain are typical, and reflect minimal soil development and sparseness of vegetation.

Bottomlands may be salt-covered flats. Eolian processes[5] are major factors in shaping desert landscapes. Cold deserts (also known as polar desert) have similar features but the main form of precipitation is snow rather than rain. Antarctica is the world's largest cold desert (composed of about 98 percent thick continental ice sheet and 2 percent barren rock). Some of the barren rock is to be found in the so-called Dry Valleys of Antarctica that almost never get snow, which can have ice-encrusted saline lakes that suggest evaporation far greater than the rare snowfall due to the strong katabatic winds[6] that evaporate even ice.

Deserts sometimes contain valuable mineral deposits that were formed in the arid environment or that were exposed by erosion. Due to extreme and consistent dryness, some deserts are ideal places for natural preservation of artifacts and fossils.

In 1953, Peveril Meigs divided desert regions on Earth into three categories according to the amount of precipitation they received. In this now widely accepted system, extremely arid lands have at least 12 consecutive months without rainfall, arid lands have less than 250 millimeters of annual rainfall, and semiarid lands have a mean annual precipitation of between 250 and 500 millimeters. Arid and extremely arid lands are deserts, and semiarid grasslands are generally referred to as steppes.

Measurement of rainfall alone can't provide an accurate definition of what a desert is because being arid also depends on evaporation which depends in part on temperature. For example, Phoenix, Arizona receives less than 250 millimeters of precipitation per year, and is immediately recognized as being located in a desert due to its arid adapted plants. The North Slope of Alaska's Brooks Range also receives less than 250 millimeters of precipitation per year, but is not generally recognized as a desert region.

There are different forms of deserts. Cold deserts can be covered in snow or ice; frozen water unavailable to plant life. These are more commonly referred to as tundra if a short season of above-freezing temperatures is experienced, or as an ice cap if the temperature remains below freezing year-round, rendering the land almost completely lifeless.

Most non-polar deserts are hot in the day and chilly at night because of the lack of the moderating effect of water. In some parts of the world, deserts are created by a rain shadow effect in which air masses lose much of their moisture as they move over a mountain range; other areas are arid by virtue of being very far from the nearest available sources of moisture.

Deserts are also classified by their geographical location and dominant weather pattern as trade wind, mid-latitude, rain shadow, coastal, monsoon, or polar deserts. Former desert areas presently in non-arid environments are paleodeserts.

Montane deserts are arid places with a very high altitude; the most prominent example is found north of the Himalaya especially in Ladakh region of Jammu and Kashmir, in parts of the Kunlun Mountains and the Tibetan Plateau. Many locations within this category have elevations exceeding 3,000 meters and the thermal regime can be hemiboreal[7]. These places owe their profound aridity (the average annual precipitation is often less than 40 mm) to being very far from the nearest available sources of moisture. Montane deserts are normally cold.

Rain shadow deserts form when tall mountain ranges block clouds from reaching areas in the direction the wind is going. As the air moves over the mountains, it cools and moisture condenses, causing precipitation on the windward side. Moisture almost never reaches the leeward side of the mountain, resulting in a desert. When that air reaches the leeward side, the air is dry, because it has already lost the majority of its moisture. The air then warms, expands, and blows across the desert. The warm, desiccated air takes with it any remaining small amounts of moisture in the desert.

Sand covers only about 20 percent of Earth's deserts. Most of the sand is in sand sheets and sand seas—vast regions of undulating dunes resembling ocean waves "frozen" in an instant of time. In general, there are six forms of deserts:

• Mountain and basin deserts
• Hamada deserts, which consist of plateau landforms
• Regs, which consist of rock pavements
• Ergs, which are formed by sand seas
• Intermontane Basins
• Badlands, which are located at the margins of arid lands comprising clay-rich soil

Nearly all desert surfaces are plains where eolian deflation—removal of fine-grained material by the wind—has exposed loose gravels consisting predominantly of pebbles but with occasional cobbles.

The remaining surfaces of arid lands are composed of exposed bedrock outcrops, desert soils, and fluvial deposits including alluvial fans, playas, desert lakes, and oases. Bedrock outcrops commonly occur as small mountains surrounded by extensive erosional plains.

Several different types of dunes exist. Barchan dunes are produced by strong winds blowing across a level surface and are crescent-shaped. Longitudinal or seif dunes are dunes that are parallel to a strong wind that blows in one general direction. Transverse dunes run at a right angle to the constant wind direction. Star dunes are star-shaped and have several ridges that spread out around a point.

Oases are vegetated areas moistened by springs, wells, or by irrigation. Many are artificial. Oases are often the only places in deserts that support crops and permanent habitation.

Deserts have a reputation for supporting very little life, but in reality deserts often have high biodiversity, including animals that remain hidden during daylight hours to control body temperature or to limit moisture needs. Some fauna includes the kangaroo rat, coyote, jack rabbit, and many lizards. Some flora includes shrubs, Prickly Pears, Desert Holly, and the Brittle bush.

Most desert plants are drought- or salt-tolerant, such as xerophytes. Some store water in their leaves, roots, and stems. Other desert plants have long taproots that penetrate to the water table if present, or have adapted to the weather by having wide-spreading roots to absorb water from a greater area of the ground. Another adaptation is the development of small, spiny leaves which shed less moisture than deciduous leaves with greater surface areas. The stems and leaves of some plants lower the surface velocity of sand-carrying winds and protect the ground from erosion. Even small fungi and microscopic plant organisms found on the soil surface (so-called cryptobiotic soil) can be a vital link in preventing erosion and providing support for other living organisms.

Deserts typically have a plant cover that is sparse but enormously diverse. The giant saguaro cacti of the Sonoran Desert provide nests for desert birds and serve as "trees" of the desert. Saguaro grow slowly but may live up to 200 years. When 9 years old, they are about 15 centimeters (6 in) high. After about 75 years, the cacti develop their first branches. When fully grown, saguaro cacti are 15 meters tall and weigh as much as 10 tons. They dot the Sonoran and reinforce the general impression of deserts as cactus-rich land.

Although cacti are often thought of as characteristic desert plants, other types of plants have adapted well to the arid environment. They include the pea and sunflower families. Cold deserts have grasses and shrubs as dominant vegetation.

 

2.8 Answer the following questions:

· What is a desert?

· Why do deserts cool so fast at night?

· What factors influence the formation of deserts?

· What is the difference between a desert and a steppe region?

· What factors should be taken into consideration when we define some area as desert?

· What are the types of deserts?

· What dune types exist?

· What is an oasis?

· How would you characterize desert flora and fauna?

2.9 ²Listen to the following podcast:

Desert Air Part1

http://hearingvoices.com/special/2007/desert/snd/hvs_07desert1.mp3

transcript: http://hearingvoices.com/transcript.php?fID=104

 

Listening Vocabulary

 

Anaheim – the second most populous city in Orange County, California.

Antelope Valley – in California, United States is located in northern Los Angeles County and the southeastern portion of Kern County.

Bed Bath & Beyond Inc. – a chain of superstores selling predominantly better quality domestics merchandise and home furnishings.

box store – a retail store that sells a limited assortment of basic grocery items, often, as at a warehouse, displayed in their original cartons in order to lower costs and prices.

burro – a small donkey used as a pack animal

Death Valley – the lowest, driest and hottest valley in the United States, located southeast of the Sierra Nevada range in the Great Basin and the Mojave Desert.

dune buggy – a small open-topped motor recreational vehicle with large tires used on beaches or sand dunes

Joshua tree – yucca type tree thriving in the Mojave Desert.

K-Mart – a chain of department stores in the United States.

Mammoth Mountain – a large lava dome complex that lies to the west of the town of Mammoth Lakes, California in the Inyo National Forest, home to the Mammoth Mountain Ski Area which is notable in that it gets an unusually large amount of snow compared to other Eastern Sierra peaks.

Marta Beckett's Amargosa Opera House – an artist and dancer from New York, Becket first visited the former railway town of Amargosa while on tour in 1964. Three years later she returned to town and bought a boarded-up theater that sat amid a group of rundown mock-Spanish colonial buildings. To compensate for the sparse audiences in the early days, Becket painted a Renaissance-era Spanish crowd on the walls and ceiling, turning the theater into a trompe l'oeil masterpiece. Now in her late 70s, Becket performs her blend of ballet, mime, and 19th-century melodrama to sellout crowds.

nugget – a solid lump of a precious metal (especially gold) as found in the earth (самородок)

outcropping – the part of a rock formation that appears above the surface of the surrounding land (выход пластов)

panhandle – an informal geographic term for an elongated tail-like protrusion of a geo-political entity, such as a subnational entity or a sovereign state. The term derives from the analogous part of a cooking pan and its use is generally confined to the United States. A panhandle is similar to a peninsula in shape, but unlike a peninsula it is not surrounded by water on three sides and connected to a geographical mainland. Instead, a panhandle is delimited by a land border on at least two sides and extends out from the larger geographical body of the administrative unit.

Pioneertown – California USA is an unincorporated small town in the Morongo Basin region of Southern California approximately 26 miles north of Palm Springs.

plywood – a laminate made of thin layers of wood (фанера).

quail – small gallinaceous game bird (перепелка, куропатка).

quartz – a hard glossy mineral consisting of silicon dioxide in crystal form.

rain shadow desert – a desert which is formed because tall mountain ranges prevent moisture-rich clouds from reaching areas on the lee, or protected side, of the range. As air rises over the mountain, water is precipitated and the air loses its moisture content. A desert is formed in the leeside "shadow" of the range.

ramshackle - in deplorable condition.

roadrunner – a speedy largely terrestrial bird found from California and Mexico to Texas distinguished by its preference for running over flying as it hunts scorpions, tarantulas, rattlesnakes, lizards, and other small animals (кукушка-подорожник).

sprawl – an aggregation or continuous network of urban communities.

supple – pliant, flexible and bending with ease.

tar paper – a heavy paper impregnated with tar and used as part of a roof for waterproofing (рубероид).

the Chihuahuan Desert – a desert that straddles the U.S.-Mexico border. On the U.S. side it occupies the valleys and basins of central and southern New Mexico, Texas west of the Pecos River and southeastern Arizona; south of the border, it covers the northern half of the Mexican state of Chihuahua, most of Coahuila, north-east portion of Durango, extreme northern portion of Zacatecas and small western portions of Nuevo León. It has an area of about 140,000 square miles (~362,600 km²). It is the third largest desert entirely within the Western Hemisphere and second largest in North America, after the Great Basin Desert.

the Mojave Desert – locally referred to as the High Desert, occupies a significant portion of southern California and smaller parts of central California, southwestern Utah, southern Nevada, and northwestern Arizona, in the United States. Named after the Mohave tribe of Native Americans.

the Sierra Nevada – (Spanish for "Snowy Range") is a mountain range located in California.

the Sonoran Desert – a North American desert which straddles part of the United States-Mexico border and covers large parts of the U.S. states of Arizona and California and the Mexican states of Sonora and Baja California. It is one of the largest and hottest deserts in North America, with an area of 311,000 km².

Watts Towers Arts Center – a centre founded by a number of citizens concerned with the restoration and preservation of the historic Towers of Simon Rodia (a collection of 17 interconnected structures built by Italian immigrant construction worker Rodia in his spare time from 1921 to 1954. The work is a superb example of non-traditional vernacular architecture.)

yuppy – a young upwardly mobile professional individual; a well-paid middle-class professional who works in a city and has a luxurious life style.

 

Answer the following questions:

· What is Ben Adair’s attitude to deserts?

· Where is he going to in a plane? What does he call “one of the quietest places of our country”?

· The sounds of what animals and birds one can hear in the desert described?

· What does Ben see driving north from Los Angeles? How does the scenery change?

· Which desert mentioned in the talk is called “rain shadow desert”?

· How does it look like?

· What does the abbreviation of “BLM” mean?

· What were people mining here in the past?

· What is the story of Burro Schmidt tunnel? How did Burro Schmidt got his nickname?

· Why did Tonie Siegert become legendary?

· Why does David Ayers disapprove of BLM plans of managing the land around Burro Schmidt tunnel?

· Why do people start thinking differently about space in the desert?

· What does Ben say his friend would love to do in Death Valley?

· What happened in Mosaic Canyon when Ben was there?

· How old are the oldest rocks at Badwater in Death Valley?

· Where does Highway 190 bisecting Death Valley dead-end?

· Due to whom this former ghost town was revived?

· What are the names of the Marta Beckett's show mentioned in the talk?

· With what does Martha Beckett compare living in New York and in the desert?

· Why did artists, musicians, old hippies migrate to the extreme south end of the Mojave Desert?

· How old is Sonny Two Feathers and where does he come from?

· What is his explanation of why people come the place?

· What is a sculptor named Noah Purifoy famous for?

· Was Ben able to meet and talk to Noah Purifoy?

2.10 Prepare your own reports about different deserts so that they include the following information:

Ø Location;

Ø Climate and type of the desert;

Ø Flora and fauna;

Ø Tourist attractions;

Ø Economic aspect.

2.11 8 Work with the following on-line quizzes:

Mountain Ranges

http://www.ilike2learn.com/ilike2learn/mountainmaps/MountainRanges.html

Mountains

http://www.ilike2learn.com/ilike2learn/mountainmaps/mountains.html

http://www.triv.net/html/Users4/u11911.htm

http://www.virted.org/MAPS&GLOBES/MountainsQuiz.html

http://www.canyonsmountains.com/quiz.php

http://www.factmonster.com/quizzes/mountains/1.html

Deserts

http://www.nature.org/earth/deserts/quiz.html

http://encarta.msn.com/quiz_276/deserts_of_the_world_quiz.html

http://news.bbc.co.uk/cbbcnews/hi/quiz/newsid_2176000/2176652.stm

http://www.funtrivia.com/playquiz/quiz106681c38bc0.html

http://members.aol.com/pakulda/dsquiz.htm

 

UNIT 3

OCEANS AND SEAS