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Bell Ringer. List three thing that you know about Africa: One about the physical geography of Africa One about the people of Africa One about Africa’s history. Physical Geography of Africa. Welcome to Africa. Second largest continent 11,700,000 sq. mi. 17% of the world’s population.
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Bell Ringer List three thing that you know about Africa: One about the physical geography of Africa One about the people of Africa One about Africa’s history
Welcome to Africa • Second largest continent 11,700,000 sq. mi. • 17% of the world’s population. • 2 ½ times the size of the U. S. • Huginormungantic.
Climate Desert Tropical Wet Tropical Wet and Dry Semiarid Marine West Coast How much of Africa is covered with rainforests or jungles?
Vegetation • Desert • Savannah • grasslands • Rain Forest • Rains up to 17 ft. per year • Covers 37 countries. • 15% of the land surface of Africa.
What internal forces are shaping Africa? Seismic Activity & Plate Tectonics
Ups and Downs Africa’s Plateaus Basins and Rivers Basin = depression Basins collect water which feed rivers. Africa’s rivers are bad for transportation. Waterfalls Rapids Gorges • Lowlands along the coast. • Most of Africa is at least 1,000 ft. above sea level. • Austin = 450 ft above sea level • Africa = Plateau Continent Victoria Falls straddles the border of Zambia and Zimbabwe. Victoria Falls is located on the Zambezi river in south central Africa. Victoria Falls has the sixth largest flow rate of all the water falls in the world and water plummets 355 feet before reaching the bottom.
Sahara Desert • North Africa • 3,500,000 square miles, bigger than “Lower 48 States” • Temperatures can range from 25*F to 130*F or more on the same day! (The very dry air of the desert holds little moisture and thus holds little heat so as soon as the sun sets, the desert cools considerably. Clear, cloudless skies also help to quickly release heat at night.) • Only 20% is sand dunes. The rest is ordinary desert. • -- A sand dune is an accumulation of sand formed by • the wind, by waves and by eroding sandstone. • Major aquifers lie deep beneath the surface in several areas. • Limits Transportation and communication between northern and southern Africa
What is the Sahel? The Sahel covers 14.9 billion hectares of the earth’s surface.. The landscape varies from flat terrain to lofty sand dunes and mountains. How much land makes up a hectare? 1 hectare is 100m x 100m = 10,000 square meter or 2.47105381 Acres • Narrow band of dry grassland used for farming and ranching – separates Desert from Tropical climate zones and has semi-arid climate. • Desertification – ruining of land due to human activities and climate changes • Caused by • Farming • Overgrazing of livestock • Cutting down too many trees for wood • Q: What is “slash and burn”? • A: Slash and burn is a farming technique in which people cut down and burn trees to create farmland. While it quickly clears land, it can destroy some plant species. Question: What is the result of the above? creation of more desert!
Kalahari Desert Southern Africa • Name means “Great Thirst” in Tswana (a local language) • Receives more precipitation than traditional deserts and therefore is host to more animals than most deserts. • Home to the African people known as the San or “Bushmen.” They were the first known human inhabitants of the Kalahari. • Habitat of Meerkats and many other unique species. The Kalahari is one of Africa’s last wildlife paradises. Animals that live in the region include hyenas, lions, meerkats, several species of antelope, and many types of birds and reptiles. Vegetation in the Kalahari consists of dry grassland and scrubby acacias. Grasses thrive during the summer rainy season.
Nile River • North and East Africa • Longest river in world, 4180 miles (Amazon is 3969, Mississippi is 3896 miles). • Two rivers, Blue Nile and White Nile, feed the river, which drains from Lake Victoria.
What are the Blue Nile and the White Nile? The two major tributaries of the Nile River are the Blue Nile and White Nile. The striking difference between them is their color and origin. The Blue Nile, which begins in the mountains of Ethiopia, starts off with a bright blue color. As it passes through Sudan, however, it picks up black sediment that gives it a darker hue. The White Nile, which begins in the forests of Rwanda and flows through Lake Victoria, is a whitish-gray color, due to the light gray sediment it carries. Although the White Nile is longer than the Blue Nile, the Blue Nile carries around two-thirds of the Nile's water supply. • About 160 million people live in the Nile River basin, in 10 countries. • Aswan Dam in Egypt, provides power and water.
Aswan Dam • Lake Nasser created by this dam • Control floods on the Nile River, but sunk ancient ruins. • Provides water and power for Egypt
Congo River Basin • Central Africa • Covered in dense jungle • 2nd Longest in Africa, 2900 miles long. The Congo Rainforest The Congo Rainforest is the 2nd largest rainforest on Earth, next to the Amazon, and stretches across the Democratic Republic of Congo (as well as other countries) with the Congo River running through it. Being in a tropical wet climate, the rainforest experiences over 60 inches of rainfall. Crops such as bananas, pineapples, cocoa, tea, and coffee are grown here.
“Killer Lakes” Africa has three lakes that are situated atop pockets of magma. These pockets keep the lake water filled with CO2. Lake Nyos, Camaroon Lake Monoun, Camaroon Lake Kivu: on the border of Rwanda and Democratic Republic of Congo in East Africa.
Lake Nyos had long been quiet before it happened. Farmers and migratory herders in the West African country of Cameroon knew the lake as large, still and blue. But on the evening of Aug. 21, 1986, farmers living near the lake heard rumbling. At the same time, a frothy spray shot hundreds of feet out of the lake, and a white cloud collected over the water. From the ground, the cloud grew to 328 feet (100 meters) tall and flowed across the land. When farmers near the lake left their houses to investigate the noise, they lost consciousness. The heavy cloud sunk into a valley, which channeled it into settlements. People in the affected areas collapsed in their tracks -- at home, on roads or in the field -- losing consciousness or dying in a few breaths. In Nyos and Kam, the first villages hit by the cloud, everyone but four inhabitants on high ground died. The valley split, and the cloud followed, killing people up to 15.5 miles (25 kilometers) away from the lake. Over the next two days, people from surrounding areas entered the valley to find the bodies of humans and cows lying on the ground. By Aug. 23, the cloud had mostly blown away, and the silence had lifted. After being unconscious for up to 36 hours, some people revived to find, horrifically, that their family members, neighbors and livestock were dead. What Happened? Scientists reasoned that CO2 had been trapped in the bottom of Lake Nyos for a long time, held down by 682 feet (208 meters) of water. On the day of the eruption, however, something external triggered the release of gas. Most likely, it was a rockslide from one of the lake's walls. When the falling rocks sunk to the bottom of the lake, they pushed up some gas. Then most of the gas bubbled up. When the CO2 concentration was 15 percent or less, people lost consciousness and later revived. Individuals who inhaled more than 15 percent CO2 stopped breathing in minutes and died. How did Lake Nyos suddenly kill 1,700 people?
Result Under the right circumstances, this gas could explode out like a Coke bottle fizzing out. This gas has killed thousands in the past, and will do so again in the future.
Serengeti Plain East Africa, between Kenya and Tanzania Most of Africa is flat grasslands, home to many wild animals (elephants, giraffes, antelope, rhinos). The most famous is the African Lion. The Serengeti Plain is one of the world’s largest savanna’s (tropical grassland), and can support millions of different animals such as zebras, lions, cheetahs, giraffes, gazelles, and many more. Rainfall in this region is seasonal and alternates between a wet and dry season. Along with the seasonal rains are dueling winds. The hot, dry harmattan comes from the Sahara and is welcomed after the wet season as it dries up the moisture in the air. Cool, humid air is also brought from the southwest. When these two winds collide tornadoes are common through the Serengeti.
Mt. Kilimanjaro • East Africa, on Serengeti Plain • Inactive volcano, 19,000 ft tall. • Has glaciers on its peak. • Popular tourist destination. The volcanic summit of Kilimanjaro is located along the eastern branch of the Great Rift Valley. Rising to 19,341 feet Kilimanjaro it is the tallest peak in Africa. Shifting tectonic plates millions of years ago formed not only the Great Rift Valley, but also Kilimanjaro. The plate movements created a series of faults where Kilimanjaro and the Great Rift Valley lie. Volcanic eruptions from Kilimanjaro helped form what is currently the Great Rift Valley.
East Africa • “Horn of Africa” slowly pulling away from Africa • The Great Rift Valley pulled apart over millions of years, faults (cracks) appeared in the earth –the land sank to form many long steep slopes called escarpments. • Escarpments separate two level land surfaces and are formed by one of two processes: erosion and faulting. • Tectonically very active, many volcanos and frequent earthquakes Great Rift Valley
Lake Victoria Lake Victoria is the largest lake in Africa and the source for the White Nile River. It is located between the east and west branches of the Great Rift Valley. Lake Victoria is located in three different countries including Uganda, Kenya, and Tanzania. It is the 2nd largest freshwater lake in the world with only Lake Superior in the United States surpassing it (sq. meters). Lake Victoria is relatively shallow at only a depth of 270 feet.
Rift Lake System Several major lakes along the Great Rift Valley, including: Lake Victoria – one source of the Nile River, very shallow (84m) Lake Tanganikya– deepest lake in Africa, 2nd largest in world by volume Lake Nyasa – largest number of freshwater fish species anywhere. Ample water supplies, so large populations in this part of Africa.
Olduvai Gorge • Part of “Great Rift Valley”, which is full of fossils. • Oldest hominid (pre-human) fossils , 2 million years old. • -Homo Habilis - Its name, which means ‘handy man’, was given in 1964 because this species was thought to represent the first stone-tool maker.Lived from approximately 2.33 to 1.4 million years ago • -Homo Erectus - oldest known early humans to have possessed modern human-like body proportions. Lived between about 1.89 million and 143,000 years ago • Discovered by Louis and Mary Leakey in 1950’s. Whole family were paleoanthropologists.