Ocean and Oceanography

(1) Ocean is a great body of salt water comprising all the oceans and seas that cover nearly three-fourths of the surface of the earth. Oceanography is the scientific study of the physical, chemical, and biological aspects of the so-called world ocean. The major goals of oceanography are to understand the geologic and geochemical processes involved in the evolution and alteration of the ocean and its basin, to evaluate the interaction of the ocean and the atmosphere, and to describe how the biological productivity in the sea is controlled.

(2) The world ocean covers 71 percent of the earth’s surface, or about 361 million sq km. Its average depth is 5,000 m, and its total volume is about 1,347,000,000 cu km. The three major subdivisions of the world ocean are the Atlantic Ocean, the Pacific Ocean, and the Indian Ocean, which are conventionally bounded by the continental masses. The two minor subdivisions of the world ocean are the Southern Ocean, bounded by the Antarctic Circumpolar Current to the north and Antarctica to the south, and the Arctic Ocean.

(3) The oceans are being looked to as a major source of food for the future. Estimates of the yearly world ocean production of organic matter amount to about 130 billion metric tons. This process begins with phytoplankton, which are photosynthetic plants that turn carbon into organic matter with the aid of sunlight; zooplankton and fish feed on phytoplankton, and each member of this part of the food web has its own predator. Most of this organic matter is recycled and reused.

(4) The harvestable amount of organic matter is a function of technology, tastes, needs, and the ability of the system to sustain this harvest. Presently, yearly harvests amount to about 82 million metric tons of fish and about 500,000 metric tons of seaweed. Estimates of the maximum harvestable amounts on a sustained-yield basis amount to about 100 million metric tons per year. Thus, predictions are that the sea can yield only about 25 percent more than the present amount of organic food resources. Food from the sea will be a good source of protein, but cannot meet the total world demand for calories in the future. The present yield of about 83 million tons per year supplies about 5.6 percent of the protein needs of the world at the present time.

(Microsoft Encarta, 2008)

1. Определите, является ли утверждение:

All the oceans and seas cover three-fifths of the earth’s surface.

a) истинным

b) ложным

c) в тексте нет информации

2. Определите, является ли утверждение:

The world ocean produces about 130 billion metric tons of organic matter per year.

a) в тексте нет информации

b) истинным

c) ложным

3. Определите, является ли утверждение:

The oceans are considered to be a major source of food that can provide the world with the total amount of calories needed in the future.

a) ложным

b) в тексте нет информации

c) истинным

4. Определите, является ли утверждение:

The mineral resources of the sea have only recently begun to be known.

a) истинным

b) в тексте нет информации

c) ложным

5. Укажите, какой части текста (1, 2, 3, 4) соответствует следующая информация:

One of the major aims of oceanography is to estimate the interaction of the ocean and the atmosphere.

a) 3

b) 2

c) 1

d) 4

6. Укажите, какой части текста (1, 2, 3, 4) соответствует следующая информация:

Estimates of the yearly fish harvest.

a) 4

b) 1

c) 3

d) 2

7. Ответьте на вопрос:

What are the three major subdivisions of the world ocean?

a) The three major subdivisions of the world ocean are the Atlantic Ocean, the Pacific Ocean, and the Southern Ocean.

b) The three major subdivisions of the world ocean are the Atlantic Ocean, the Indian Ocean, and the Arctic Ocean.

c) The three major subdivisions of the world ocean are the Atlantic Ocean, the Indian Ocean, and the Pacific Ocean.

d) The three major subdivisions of the world ocean are the Atlantic Ocean, the Southern Ocean, and the Indian Ocean.

---

Дата добавления: 2015-10-30