Glaciers and the Water Cycle Quiz

Grade 8 Science: Unit 1 - Water Systems on Earth, Chapter 1

• The unit focuses on Earth's water systems
• Various images are included, such as the Churchill River, a large ocean wave, and a diagram of the water cycle.

Water Distribution

• Earth's water is primarily saline (97%) and found in oceans.
• Freshwater accounts for 3% of Earth's water.
• Most of the freshwater is frozen in ice caps and glaciers (68.7%).
• A small portion of freshwater is found in groundwater (30.1%).
• Rivers, lakes, and swamps make up a small portion of freshwater (2%, 87%, and 11%, respectively).
• Only 1% of Earth's freshwater is readily available for use.

Uses of Water

• Water is used for household purposes.
• Water is used for personal needs.
• Water is used for recreational activities.

The Water Cycle

• A continuous process.
• Driven by the sun's energy.
• Water in the ocean evaporates and condenses into clouds.
• Water falls back to Earth as precipitation (rain or snow).
• Some precipitation soaks into the ground as groundwater.
• Some precipitation runs off the surface as runoff.

Water Properties (Ocean Water vs. Fresh Water)

• Salinity: The amount of dissolved salt in a specific amount of water.
  • Ocean water has a higher salinity (average 35 parts per thousand) than fresh water.
  • Salt comes from dissolved solids in the ground and volcanic activity.
• Density: The amount of mass in a unit volume.
  • Ocean water is denser than fresh water due to its higher salt content.
• Freezing Point: The temperature at which a liquid turns to a solid.
  • Fresh water freezes at 0°C.
  • Salt water freezes at -1.9°C.

Sources of Fresh Water

• Lakes, ponds, and wetlands
• Streams and rivers
• Groundwater: Precipitation that soaks into the ground.
• Glaciers: Moving bodies of snow and ice in cold areas.
• Drainage basins (watersheds): Areas of land that drain into a body of water (e.g. a river, lake or ocean)

Core Lab Activities

• "Salinity's Effect on Water Density"
• "Temperature & Water Density"

Effects of Global Warming on Glaciers

• In the last 100 years, the average surface temperature has increased by 0.5°C.
• The world's glaciers are melting at a faster rate.
• Glaciers store vast amounts of water, and their melting contributes to rising sea levels.

Impact of Glacier Melt

• Rising ocean water levels
• Flooding in river systems