By far the greatest proportion of land is in the northern hemisphere, and in temperate latitudes. Broadly speaking, the northern hemisphere is the hemisphere of land, and the southern hemisphere is the hemisphere of ocean. The earth could be bisected in such a way that one hemisphere contained almost no land, while the other was composed almost equally of land and water.
LOCATION OF THE
CONTINENTS
The greater part of the land on the earth’s surface is grouped into two great hemispheres, the Old and the New World. The former and far larger of these consists of Eurasia in the north, separated by ill-defined boundaries from Europe to the west and Asia to the east, and of Africa in the south, united to Eurasia by the narrow neck of the isthmus of Suez. The hemisphere of the New World is divided into North America and South America, united by the long, narrow isthmus of Central America. The island of Australia is also reckoned as a continent. It is believed that an island continent, Antarctica, surrounds the South Pole. Of islands not reckoned as continents, the largest is the polar island of Greenland.
CERTAIN RESEMBLANCES OF
THE CONTINENTS
In comparing the continents, we at once notice certain resemblances. The first is the tapering to the south, which is seen in Greenland, North and South America, Africa, and Australia (Tasmania). Another is the southward-running peninsulas which characterize Europe and Asia. We may notice, too, that the general lines of the Old World, broad in the north, tapering in the south, resemble those of the New World, especially if we include Australia (Tasmania), and compare its position with that of South America. There is also a certain uniformity in the distribution of relief. Notice the so-called Mid-World and Pacific Mountain systems, which may be traced in the mountains of Central Europe, North Africa, Central Asia, the islands of the Pacific from Japan to New Guinea, and the lofty mountains of North, Central, and South America.
DIAGRAM SHOWING AVERAGE HEIGHT OF THE CONTINENTS
COMPARISON OF THE CONTINENTS
| Continent | Asia | Africa | North America | South America | Europe | Australia | All Land | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Area (million square miles) | 16 | .4 | 11 | .1 | 7 | .6 | 6 | .8 | 3 | .7 | 3 | .0 | 55 | .0 | ||
| Average Height (feet) | 3, | 000 | 2, | 500 | 1, | 900 | 2, | 000 | 940 | 800 | 2, | 100 | ||||
| Highest Point (feet) | 29, | 000 | 18, | 800 | 18, | 200 | 22, | 400 | 18, | 500 | 7, | 200 | 29, | 000 | ||
| Percentage at Various Altitudes (feet) | ||||||||||||||||
| Below Sea-Level | 1 | .4 | 0 | .1 | 0 | .05 | 0 | .0 | 1 | .8 | 0 | .0 | 0 | .6 | ||
| 0 | to | 600 feet | 23 | .3 | 12 | .5 | 32 | .25 | 40 | .0 | 53 | .8 | 29 | .8 | 26 | .7 |
| 600 | to | 1,500 feet | 16 | .0 | 34 | .8 | 32 | .1 | 26 | .8 | 27 | .0 | 64 | .3 | 27 | .8 |
| 1,500 | to | 3,000 feet | 21 | .7 | 27 | .6 | 13 | .3 | 16 | .8 | 10 | .0 | 4 | .1 | 19 | .3 |
| 3,000 | to | 6,000 feet | 21 | .8 | 21 | .8 | 13 | .2 | 7 | .0 | 5 | .5 | 1 | .5 | 17 | .0 |
| 6,000 | to | 12,000 feet | 10 | .0 | 2 | .8 | 8 | .4 | 5 | .0 | 1 | .7 | 0 | .3 | 6 | .0 |
| Above 12,000 feet | 5 | .8 | 0 | .4 | 0 | .7 | 4 | .4 | 0 | .2 | 0 | .0 | 2 | .6 | ||