CONTENTS IO Blue Planet Rivers A Rivers Source River Stages What Is a Lake Lakes of the World Changing Lakes Oceans I2 14 16 18 Ocean Waters 20 22 Tides Ocean Depths Pollution 24 26 28 30 Using Water Glossary For More Information Index 31 32
BLUE PLANET Viewed from space Earth looks mostly blue with scattered brown patches That is because almost three quarters of Earth's surface is covered in water Less than 1 percent of this water is freshwater that we can drink and use The rest is mostly salt water in the oceans and some is frozen at the North and South Poles Can you see why Earth people call is the blue
A Water in the oceans makes up nearly 98 percent of all the water on Earth THINRABOUTI We cannot drink seawater because it has so much salt in it Instead While you read of quenching our thirst seawater this book think would dry us out The body tries about how rivers lakes and oceans to get rid of salt by making us produce more urine If the body are connected loses too much water it can no longer
