Africa is the second largest continent on Earth, spanning over 11.6 million square miles. Straddling the equator at about its midpoint, it covers a multitude of climate zones, including tropical rainforest, Mediterranean, savannah, desert, steppe, and highland climates. Africa is surrounded by the Atlantic Ocean, Indian Ocean, Red Sea, and the Mediterranean Sea. It includes the Nile River which rivals the Amazon for the title of the longest river in the world (depending on how it is measured). The massive Sahara is the largest desert in the world: 3,000 miles across and covering 3.5 million square miles. The Sahara stretches across the northern third of the continent. The smaller Kalahari Desert in southern Africa is a rich mix of wildlife and vegetation.
Africa's major climate and vegetation areas can be roughly identified by the amount of rainfall each area receives. Early civilizations developed where rainfall was plentiful, or near lakes or along rivers. Near the equator, orchids and ferns grow amid the canopy of trees that tower up to 150 feet above the floor of the tropical rainforests - so thick that sunlight cannot reach the forest floor. Drier tropical grasslands, known as savannas cover nearly half of the continent. Further north and south of the savannas are drier steppe climates with low-growing grasses and acacia trees. Grasses and trees can even be found in isolated deserts, such as the Kalahari in southern Africa, where little rain falls. In southern Africa deserts give way to cool fertile highlands rimmed by coastal plains having Mediterranea-type climates.
Africa's overall elevation is higher than that of any other continent. High plateaus cover the continent, rising in elevation from the coast inland and from west to east. In many parts of the region, this high flat land falls in dramatic cliffs to narrow, unbroken coastlines having few inlets, large bays, gulfs, or natural harbors.
Shifting tectonic plates formed the Great Rift Valley, a long, narrow break in the Earth's surface which runs from Syria to Mozambique. Formed by the folding and fracturing of Earth's crust over the last 60 million years, the valley area holds chains of sparkling lakes, such as Lake Vitoria, Africa's largest lake. The valley's rich volcanic soil creates some of Africa's best farmland. East of the valley, rising above plateau areas, are lofty, snow-capped mountains. One of the most impressive of these is Kilimanjaro - Africa's tallest mountain with a height of 19,340 feet.
Extensive river systems such as the Congo, Niger, and Zambezi wind through Africa south of the Sahara. The Congo, Africa's second longest river, and its tributaries traverse the vast rainforests of the Congo Basin, eventually draining into the South Atlantic Ocean. Sharp escarpments and steep cataracts on some rivers have posed obstacles to travel over the centuries. Limited river travel and few natural harbors isolated early African civilizations and made foreign invasions difficult in some areas. Rivers, however, have long been an important means of local transportation for people in the region, especially in areas where dense rainforest prevails.
Africa is rich in natural resources, including oil, gold, uranium, and diamonds. The continent also has an abundance of plants and animal species. The preservation of these diverse biological resources has become a global concern. Many countries are working hard to achieve a balance between conserving habitats and meeting economic needs.
LEARNING
Read Geography of the Human and Physical World pages 365-371, 484-488, 504-510, 530-534, 554-558, 576-580. Then look through the following links.
Sahara Desert
Kalahari Desert
Nile River
Desertification
Sahel region
Madagascar
Video: Congo Basin
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