TEST REVIEW ON WEATHERING, SOIL AND WATER

WEATHERING Mechanical Weathering Is the breakdown of material into smaller pieces by physical means Types of Mechanical Weathering Ice: Freezing and thawing of soil and rock is Frost action or Ice wedging Abrasion: The grinding and wearing away of rock surfaces by Wind, Water, and Gravity. Plants: Tree roots are strong enough to slowly break soil and rock. Animals: When animals burrow in the ground, they break up soil and loosen rocks to be exposed to further weathering.

WEATHERING (Cont.) Chemical Weathering The process by which material breaks down due to chemical reactions Common Agents of Chemical Weathering Water, Weak Acids, and Air: Can slowly or rapidly dissolve the chemical bonds between minerals to eventually produce sediment. Scientist measure acid concentration (or acidity) by using a pH scale from 0 to 14. Solutions that have a pH of less than 7 are acidic. Solution that have a pH of greater than 7 are basic. Acid Precipitation: Is a chemical reaction caused by Rain, Sleet, or Snow that contains a higher than normal acid concentration. Acid precipitation can be caused naturally by Volcanoes or by Fossil Fuels and Air Pollution.

WEATHERING (Cont.) Rates of Weathering Differential Weathering: The process by which softer, less weather resistant rocks wear away and leave harder, more weather resistant rocks behind. Surface Area: The greater the surface area the more weathering can take place. Climate: The more humid the climate the higher the rate of both mechanical and chemical weathering. Elevation: Materials at higher elevations are exposed to more wind, rain, and ice than rocks and materials at lower elevations.

Soil Soil Is a loose mixture of small mineral fragments, organic material, water, and air that can support the growth of vegetation. Parent Rock: The source of mineral fragments, formed from weathering, in the soil. Bedrock: is the layer of rock beneath the soil. Transported Soil: Soil that is blown, washed, or moved away by natural or man-made means. Wind and the movement of glaciers are examples natural means. Construction and mining activities are examples man-made means.

Soil (cont.) Soil Conservation Is the method to maintain the fertility of the soil by protecting the soil from erosion and nutrient loss. Erosion: The process by which wind, water, or gravity transport soil and sediment from one location to another. Land Degradation: Occurs when the soil has been damaged due to overuse, poor farming techniques, or overgrazing to point that vegetation will not grow and the area becomes like a desert. Leaching (page 52): Water dissolves and carries nutrients in the topsoil through the different Soil Horizons. Soil pH: The pH of the soil influences how nutrients dissolve. Certain nutrients dissolve at a high pH (basic) and some at a low pH (acidic) Separate plants may need different nutrients….So the right soil pH is required for certain plants.

Soil (Cont.) Soil Conservation Techniques (page 58): Contour Plowing: Helps prevent erosion. Terracing: Prevents erosion on steep slopes. No-till farming: Prevents erosion and nutrient removal (slows leaching) by providing cover during run-off periods. Cover crop: Restores nutrients to the soil. In Syracuse (flat land), out of the above techniques, what do you think the best soil conservation technique(s) would be?

Water Water Cycle( page 71) Condensation: Water vapor cools and changes into water droplets that form clouds in the atmosphere. Water loses energy during condensation. Precipitation: Rain, snow, sleet or hail that falls from the clouds. Evaporation: Water from the oceans and the Earth’s surface changes into water vapor. Water gains energy during water evaporation. Percolation: is the downward movement of water through pores and other spaces due to gravity. Runoff: The precipitation that flows over land into streams and rivers.

Four states of matter (a look back at phase changes) Remember: Enthalpy is a measure of energy. So water gains or loses energy When in turns from vapor to rain or from water to vapor. This is a change in a phase of matter and energy is therefore lost or gained!

Water (cont.) River Systems Watershed : The area of land that is drained by a water system. Tributary : A stream that flow into a lake or larger stream. Divide : The boundary between drainage areas that have streams that flow in opposite directions. Channel: The path that a stream follows. Types of Rivers (pages 75 and 76): Youthful, Mature, Old, and Rejuvenated. Polar Ice Caps : Where the majority of the world’s fresh water is located.

Water (cont.) Water Health Dissolved Oxygen: The concentration of O2 that is dissolved in the water. If dissolved oxygen is to low, it can cause harm to aquatic life. Nitrates : Naturally occurring compounds of nitrogen and oxygen. If nitrate levels are elevated, it can be harmful to aquatic life. Alkalinity : Water’s ability to neutralize acid. Acids and other acid wastes can harm aquatic life. It is important for water to keep pH levels above 6.0.

Water (cont.) (Waste) Water Treatment Sewage Treatment Plants (page 90) : A water treatment facility that cleans the waste materials found in water that comes from sewers or drains. Septic Tanks (page 91) : is a large underground tank that separates solid waste from liquids for a household. According to the pie chart graph on page 91 what could you and your family do to conserve the most water?