SUB SAHARAN AFRICA

- Continent: AFRICA - Hemispheres: N, S, E, W - Landmass: 11,677,240 sq. mi. - Population: 1,000,000, Countries: 55

A. 2 nd LARGEST CONTINENT in the world B. Known as the “PLATEAU CONTINENT” 1. Interior of continent = a vast plateau (highest in the east & south/ drops sharply at the coast) What is a PLATEAU? _________________________________ __________________________________

PLATEAU A raised, flat area of land bounded on one or more sides by cliffs or steep slopes.

2. AFRICAN CONTINENT: almost entirely surrounded by a low, narrow coastal plain. - The sharp, steep rise that separates the coastal plain from the elevated plateau is called an escarpment. - The steep cliff marking the edge of the continental plateau in the country of South Africa is called The Great Escarpment.

4.Africa as a continent has the highest overall elevation of all continents (average plateau elevation = feet above sea level). 5. Mountains: individual mountains/ not ranges/ mainly in the East & North. Many are volcanic mountains. - Elevation is the key to their temperature. 6. Africa’s rivers contain many cataracts (multiple waterfalls at the edge of steep escarpments). (Escarpments & cataracts negatively affect travel & the economy; rapids & gorges make navigation difficult).

C. THE_GREAT RIFT VALLEY 1.One of the world’s natural wonders; about 4,000 + miles long 2. Begins in the countries of JORDAN & Syria (SW Asia), goes through the RED Sea, extends south through eastern Africa and ends in MOZAMBIQUE. 3. Valley is a RIFT FAULT formed over millions of years when two of the earth’s CONTINENTAL PLATES pulled apart. Not In Notes: (a section of the earth’s surface sinks into the crack & forms long, thin valleys).

4. Can be up to 50 + miles wide; walls of the valley can be up to about one mile high. 5. Valley Floor: often barren/ many extinct VOLCANOES and a surface covered with volcanic LAVA and ash. Makes soil very fertile. 6. There is a large string of LONG, DEEP, NATURAL LAKES through the valley (Lakes Albert, Edward & Tanganyika). Lake Tanganyika is the longest freshwater lake in the world (over 400 miles long)

7.LAKE VICTORIA is NOT part of the Great Rift Valley. It is the largest lake in Africa/ Location: in a basin between the two prongs of the Great Rift Valley. Lake Victoria is the origin of the White Nile River; flows northward to Egypt & the Mediterranean Sea.

D. BASINS: Across the Plateau of Africa, there are several deep basins (depressions) in the land where water collects; can measure more than 600 miles across and as deep as 5,000 feet. (EX: Congo Basin/Okavango Basin) Refer to map on p. 415)

E. CLIMATE & VEGETATION (Sub Saharan Africa) 1.Similar bands of climate & vegetation stretch across Africa NORTH & SOUTH of the EQUATOR. (Mirror regions N & S) 2. RAIN FOREST = Vegetation region along the Equator. a. Hot and wet. A region of ONE SEASON. b. The rainforest is shrinking each year. (25,000 football fields of rainforests disappear in the Congo rainforests each week). 10%

3.GRASSLANDS (also called SAVANNA) a.Located NORTH & SOUTH OF RAINFORESTS. b. Usually LONG & SHORT GRASSES w WIDELY SCATTERED TREES. c.Climate is HOT all year round with TWO seasons: LONG, DRY SEASONS SEPARATED BY TORRENTIAL WET SEASONS. 65%

4. DESERTS: SEMI-ARID & ARID LANDS a. Deserts: usually have 10 INCHES OR LESS OF RAIN PER YEAR. b. In the North: SAHARA and the SAHEL* * Sahel means “shore of the desert”/ southern border of the Sahara. c. In the South: THE KALIHARI DESERT. d. In the Southwest: THE NAMIB DESERT. 25%

5. Mediterranean Coastal Plain: along the Northern coastal plain of Africa (north of the Sahara); rain in winter months of December & January. and Mediterranean Coastal Plain: along the far Southern coastal plain of Africa; rain in winter months of June & July.

Most of Africa is HOT (temperature) all year long. ELEVATION can affect the temperature as much as latitude. RAINFALL varies greatly/ amounts vary with the distance from the EQUATOR. The closer to the Equator the MORE rainy; the further away, the LESS rain (EXCEPT at the COAST where a Mediterranean Climate can prevail).

The longest crack (rift) in the earth’s surface is the Great Rift Valley. 25M years ago, the shift of tectonic plates tore a rift in the earth’s crust, splitting Arabian Peninsula away from Africa (created Red Sea) & forming many canyons in eastern Africa, many w deep, long lakes. Rift is 4,000+ mile long, extending north to Syria & Jordan in SW Asia. Rift is hidden by erosion, mountains and plateaus. At sites along the valley, fossil evidence of earliest humans has been discovered. See next slide, also

Map of East Africa w active volcanoes (red triangles). TheEast Africa Afar Triangle (shaded in center) shows three plates pulling apart: the Arabian Plate and two parts of the African Plate — the Nubian and African Plate SomaliSomali — splitting along the East African Rift Zone. EAST AFRICAN RIFT (EAR) began splitting 25 M years ago