Chapter 1 - Lesson 2 Streams and Rivers, Lakes Chapter 1 The Earth’s Bodies of Water

Water covers more than 70% of the Earth Water is in the ground and in the air we breathe People, Plants, and Animals all need water to live Streams and Rivers page 26 Weathering - is the process of breaking up rocks into smaller pieces called sediment

Streams are bodies of water that flow over land in a channel Most streams begin on high ground, among hills or mountains The sources of a stream usually consist of melting snow/ice or an overflowing lake At the end of a stream is the mouth which empties into another body of water Streams and Rivers

Streams can be as small as a shallow brook Or as large as a river, the largest and most important streams Most rivers form from many smaller streams coming together, these are called tributaries Streams and Rivers Tributaries – are streams or rivers that flow into a larger stream or river

The more tributaries that empty into a river the larger the river grows Together the river and its tributaries are called a river system Streams and Rivers River System – a river and all of its tributaries

Each continent, except Antarctica, has major rivers and river systems. Africa has the Nile, Asia has the Yangtze, Australia has the Murray, Europe has the Danube, North America has the Mississippi, and South America has the Amazon Streams and Rivers

The Nile is the Earth’s longest river, it flows from Central Africa to the Mediterranean Sea The Amazon is the Earth’s largest river, carrying more water than the Mississippi, Nile and Yangtze combined River Systems carry or drain water away from the land around them (drainage basin) Rivers are important for many reasons including drinking, cleaning, travel and trade Streams and Rivers, Lakes Drainage Basin – Land drained by a river system

Streams and Rivers Drainage Basin

Why did many of the world’s first settlements form along rivers? (pg.27)

Lakes are bodies of water surrounded by land The word lake comes from the Greek language meaning hole because most lakes are holes in the Earth that fill with water Lakes exist on every continent except Antartica The greatest amount of lakes exist where there was once many glaciers such as North America and northern Europe Lakes

During the last Ice Age, glaciers gouged huge holes in the Earth and the holes filled with the water from the melted glaciers Lakes also form where rainwater collects in huge holes made in other ways Crater Lake in Oregon was formed in a crater of an extinct volcano Lakes

Lake Baikal in Russia is the deepest lake on Earth measuring 5,315 feet deep it was formed in a huge crack in the Earth’s crust called a rift Lakes Rift – a long and deep crack in the Earth

North America has the most lakes out of all of the continents The largest of the North American lakes are the Great Lakes One fifth of all of the fresh water on the Earth’s surface is found in the Great Lakes Lakes H – Huron O – Ontario M – Michigan E – Erie S – Superior

There are some large bodies of water called seas that are actually lakes The difference is that they are not fresh water, but salt water and that is why they are called seas instead of lakes The Dead Sea, Sea of Galilee, and the Caspian Sea are lakes The lowest lying lake is the Dead Sea between Israel and Jordan The highest lake is Lake Titicaca in South America Lakes

The Dead Sea

Lakes Lake Titicaca

Not all lakes are made by nature Some are man-made and are called resevoirs People build dams to control river flooding or to generate electricity Lakes Reservoir – a lake that forms behind a human made dam

Terms to Know Reservoir Rift Drainage basin River system Tributaries How did Ice Age glaciers form lakes in North America and Europe? (pg. 28)