1. 23.1 Fresh Water
71% of Earth is covered with water, 3% is fresh
A. Water Cycle = continuous cycling of water on Earth
1. Evaporation
Sunlight heats liquid water and converts it to gas
Transpiration = water released by plants
2. Condensation
Water vapor cools and condenses back to liquid
3. Precipitation
Water droplets or ice falls to the ground

2. B. Fresh Water
1. The Atmosphere
Exists as water vapor or clouds
Stays only a short time before precipitation
2. Streams and Rivers
Rain falls
Some becomes runoff = water that flows over Earth’s surface
May flow into a stream or tributary, then to a river

3. Watershed = area of land that contributes water to a river system
3. Ponds and Lakes
Usually drain into streams

4. 4. Water beneath the surface
Near surface, spaces in rock and soil are filled with air
Saturated zone = where pore spaces are filled with groundwater
Water table = top of the saturated zone
Groundwater = form of most fresh water, water found underground within cracks and between particles of rock and soil

5. Permeable = rock that water can pass through (limestone, sandstone)
Aquifer = permeable rock that is saturated with water
Impermeable = rock that doesn’t allow water to pass (shale, granite)

6. 5. Glaciers and Icebergs
Glaciers form in areas where more snow falls than melts
Weight presses snow together to form ice
Weight causes flow downhill
Icebergs form when glaciers
break off
into the
ocean

7. 23.2 Weathering and Mass Movement
A. Erosion = process that wears down and carries away rock and soil
Acts through weathering, gravity, streams, groundwater, glaciers, wind, waves, living things

8. Central park is mostly clay and does not provide good support for sky scrapers… lucky for the residents!

9. B. Weathering = process by which rocks are
B. Weathering = process by which rocks are chemically altered or physically broken down
1. Mechanical Weathering = physically breaking rock
Frost wedging = expansion when ice freezes
Abrasion = scraping
Plant root growth

10. 2. Chemical Weathering = breaking down due to chemical reactions
All minerals dissolve in water
Rain is also slightly acidic
Acid will react with minerals like calcite, limestone, marble (concrete, travertine…)
Mineral is eroded, may form caves
Neutralization happens which can reduce the effects of acid rain
Bubbles
2HCl + CaCO3 -> CO2 + CaCl2 + H2O

11. Sink hole formation from chemical weathering of Calcium carbonate substrate

14. Formation of rust is another example of chemical weathering
C. Rates of Weathering
1. Temperature
Chemical weathering occurs more rapidly at high temperatures
Mechanical weathering occurs more rapidly if temperatures change a lot
2. Availability of water
More water, more weathering
Type of rock exposed at the surface
Stop here for CT TASK

15. D. Mass Movement
Mass movement = downward movement of rock and soil
1. Landslides = rapid movement of large
amounts of rock and soil
2. Mudflows = rapid movement of rock and
soil mixed with water
3. Creep = soil gradually moves
down a slope
4. Slumping = weak layers of soil or rock
move down as a unit

16. E. Effects of Erosion
1. On-site
Remove nutrients, fertilizers from soil
Loss of structure and stability, loss of topsoil
Change in texture and water-holding capacity
2. Off-site
Prevent seed germination, bury plants
Destroy roads, buildings, bridges
Sedimentation could block streams and require dredging
Make streams cloudy, blocking light, prevent photosynthesis
Wash contaminants/pollutants into waterways, water purification problems

17. F. Preventing Erosion
1. Using a physical barrier to divert energy of wind or water
2. Planting vegetation, terracing, contour plowing, no-till farming, mulching
Waterbreak
Reforestation
Mulching
Windbreak
Wire Fencing
Terracing