Chapter 3, Section 3

 The continuous movement of water into the air, onto land, and then back to water sources.  Evaporation  Condensation  Precipitation

 Liquid water is heated by the sun and then rises into the atmosphere.  Water continually evaporates from Earth’s oceans, lakes, streams, and soil.  Majority of water evaporates from the oceans.

 Water vapor forms water droplets on dust particles.  Water droplets form clouds, in which the droplets collide, stick together, create heavier and larger droplets.

 After the larger droplets form during condensation, they fall from the clouds as: ◦ Rain ◦ Snow ◦ Sleet ◦ Hail

The Water Cycle

The Earth’s Oceans, Fresh Water & Groundwater

 The hydrosphere includes all of the water on or near the Earth’s surface.  This includes water in the oceans, lakes, rivers, wetlands, polar ice caps, soil, rock layers beneath Earth’s surface, and clouds.

 All of the ocean’s are joined.  World Ocean – The single, large, interconnected body of water.  70% of Earth’s surface  Largest Ocean = Pacific Ocean  Smallest Ocean = Arctic Ocean

 Ocean water contains more salts than fresh water.  Most of the salt is sodium chloride.  The salt comes from: ◦ dissolved out of rocks on land and carried down the rivers into the oceans. ◦ Underwater volcanic eruptions

 3% of all the water on Earth is fresh water.  Most is locked up in icecaps and glaciers  Also found in lakes, rivers, wetlands, the soil, rock layers below the surface, in the atmosphere

 A network of streams that drains an area of land  Contains all the land drained by the river including the main river and its tributaries  Tributaries – smaller streams or rivers that flow into larger ones

 Rain and melting snow sink into ground and run off the land.  Some ends up in streams and rivers but most trickles down through the ground and collects as groundwater.  Less than 1% of all water on Earth.

 Aquifer - A rock layer that stores and allows the flow of groundwater.  Recharge Zone – The surface of the land where water enters an aquifer.

Life on Earth

 Narrow layer around Earth’s surface in which life can exist. ◦ The uppermost part of the geosphere ◦ Most of the hydrosphere ◦ Lower part of the atmosphere.  Biosphere is located near the Earth’s surface because most of the sunlight is available near the surface.

 Most life requires liquid water, moderate temperatures, and a source of energy.  The materials that organisms require must be continually recycled.  Gravity allows a planet to maintain an atmosphere.

Open and Closed Systems

 When an organism in the biosphere dies, its body is broken down and the matter in its body becomes available to other organisms.  This matter is continually recycled.  Energy must be supplied constantly.

 Closed system ◦ Energy enters and leaves the system, but matter does not. ◦ Earth is a closed system because the only thing that enters is energy from the sun and the only thing that leaves is heat.  Open System ◦ Both matter and energy are exchanged between a system and the surrounding environment. ◦ The Earth was once an open system. ◦ Matter was added to early Earth as it was hit by comets and meteorites.