EARTHS CYCLES IN ACTION earth's WATER CYCLE By Diane Dakers Water cycle CRABTREE Publishing Company www crabtreebooks com
CHAPTER 1 Water Water Everywhere Water is all around us About 70 percent of Earth is covered with water Look at a photo of the planet from space All the blue parts are water That’s why Earth is sometimes called the blue planet Water is the most abundant or plentiful substance on Earth and one of the most important Water World About 97 percent of all the water on Earth is contained in five oceans the Atlantic Pacific Indian Arctic and Antarctic Ocean water is salt water Only about 3 percent of the planet’s water is fresh water That’s the kind of water that people and animals drink About two-thirds of Earth’s fresh water is not available to drink because it is frozen as ice in the Arctic and in Antarctica Just one-third of all fresh water is found in rivers and lakes and underground This adds up to only about one percent of all the world’s water being available as drinking water 4 This photo from space shows Earth’s western hemisphere It also dramatically illustrates why we call our world which is 70 percent covered with water the blue planet The clouds that swirl around the planet are also filled with water They play a major role in Earth’s weather patterns and in the water cycle
This underground water is called groundwater Water exists as a gas in our air In this form it is called water vapor Up to four percent of our air is made of gaseous water or water vapor This amount varies from day to day and place to place Water is the only substance on Earth that naturally exists in three states solid liquid and gas Solid water takes the form of ice or snow In addition to the ice and snow around Earth’s North and South Poles glaciers and icebergs are made of solid water Liquid water is what fills our oceans lakes rivers and streams Water also soaks into the ground where gravity pulls it deeper and deeper Sea ice Arctic Ocean 5 Above This photo of an iceberg in Antarctica shows water in all three of its states liquid blue sea solid the iceberg and gas invisible water vapor in the air Inset Earth’s North Pole is covered with floating sea ice over the Arctic Ocean
