Transcript Water
SOL 6.5 Water and its effects on Earth What do you know about water? Read and complete Chapter 4 Lesson 3 Water ? Water is a polar molecule: it has a negative side and a positive side. This makes water molecules “stick” together. Water dissolves almost everything: called the universal solvent Water is the only substance that exists in all three states, solid liquid and gas. Solid water is less dense than liquid water Properties of Water Because ice floats on liquid water it helps water organisms survive freezing air temperatures. Water absorbs thermal energy and holds it, thus land areas near large bodies of water have milder climates than land areas farther inland. Our oceans hold in heat which prevents Earth from cooling to temperatures that would destroy life on this planet. Water Continued Just How Much??? 100% of water on earth. Subtract 97% that is salt water Equals 3% Fresh water 76 % of that 3% is locked up in the form of ice in the polar regions. The remaining fresh water is found in: lakes, rivers, and aquifers deep underground Chapter 6 Lesson 1: read and complete. Fresh Water Ice 76% Ground Water: Deep and Shallow Lakes and Rivers 23% Water Vapor 0.037% 0.34% Fresh Water 80% 70% 60% 50% 40% 30% 20% 10% 0% 76% Ice Underground Lakes/rivers Water Vapor 23% 0.34%0.04% Agriculture Industry Transportation Recreation Drink, bathe, cook and use water many times each day for many other things. How do we use water??? Water: Effects on Land windows live photo gallery Read and Complete Chapter 11 Lesson 1 Weathering breaks down rock into smaller and smaller pieces. Heat, Cold, water, and ice all contribute to weathering. There are two main types of weathering ◦ Mechanical weathering ◦ Chemical weathering The Effects of Weathering Abrasion: Sand and other rock particles that are carried by wind, water, or ice can wear away exposed rock surfaces. Animal Actions: Animals that burrow into the ground like moles, groundhogs, prairie dogs and some insects loosen and break apart rocks in the soil. Mechanical Weathering 2 Chemical weathering breaks down rock by chemical changes. The agents of Chemical weathering include: ◦ ◦ ◦ ◦ ◦ Water Oxygen Carbon dioxide living organisms acid rain Water weathers rock by dissolving it. Oxygen weathers rock that has iron particles in it through oxidation, (rust) Carbon Dioxide breaks down rock by mixing with water making a weak acid called carbonic acid that weathers marble and limestone. Chemical Weathering Living organisms: Plants make weak acids as they push through rock and weaken the rock. Acid Rain: sulfur, carbon, and nitrogen compounds in the air from burning fossil fuel mix with rain water and make sulfuric and nitric acid solutions that wear away rock. Chemical Weathering 2 There are two factors that effect the rate of weathering. ◦ Type of rock- rocks that are more permeable and contain minerals weather more quickly than rocks that are less permeable. ◦ Climate- hot and wet climates cause rock to weather more quickly than cool dry climates. Rate of Weathering Weathering Is About… the process that breaks down rock and other substances at Earth’ Surface Prentice Hall text. pp.92-97 Type 1 Type 2 Mechanical Weathering Chemical Weathering Essential Details Essential Details Abrasion Freezing and thawing Release of pressure Water oxygen Carbon Dioxide Growth of plants Living organisms Actions of animals Acid Rain Factors that determine the rate of weathering are type of rock and climate. So What: Weathering of rock produces soil that makes plants grow and is essential to sustaining life EROSION Sediment: Material moved by erosion Deposition: Process where erosion lays down sediment. Mass Movement Mudflow:rapid movement of water rock and soil Landslides: movement of rock and soil Slump: a mass of rock and soil slips down a slope Creep: very slow movement of rock and soil down a slope Erosion and Mass Movement Chapter 11 Lesson 2 Stream formation Rills: tiny grooves made by trickles of water Gullies: larger grooves made by many rills Streams: created by the water from Gullies Trubutary: smaller streams or rivers that flow into larger rivers. Stream shape Meanders: a looplike bend in a river caused by erosion. Oxbow lake: a meander that has been cut off from the river Flood plain: flat wide area of land along a river. Erosion: Water Chapter 11 Lesson 3 Glaciers are large masses of ice that move slowly over the land. Plucking: Occurs when a glacier picks up rocks and moves them down hill. When a glacier melts it deposits sediment and creates various landforms: ◦ Till ◦ Moraine ◦ kettles Glacial Erosion Chapter 11 Lesson 4 Waves erode the shore by breaking down rock and moving sand and other sediment creating many landforms. ◦ ◦ ◦ ◦ ◦ ◦ ◦ Beaches Sea caves Headlands Sea arches Sea stacks Spit sandbars Longshore drift: occurs when sediment moves down the beach with the current. Wave Erosion: Chapter 11 Lesson 5 Erosion Source: Paul Fuqua Copyright 2003 Erosion is the process by which water, ice, wind, or gravity moves fragments of rock and soil. Moving water is the major agent of the erosion that has shaped Earth’s land surface. Source: Paul Fuqua Copyright 2003 Erosion drops. begins with rain ◦Some sink into the soil ◦Some evaporate ◦Plants use some ◦Some run into already existing bodies of water, such as streams, rivers, lakes and waterfalls. Water on land All the remaining water that moves over the earth is runoff. Runoff carries particles of soil and rock with it, moving downhill because of gravity. Tiny grooves are formed in the earth by runoff. These are called rills. • When rills flow into one another they form a gully. • A gully is a large groove, or channel that carries runoff after a rain storm. Gully As water moves through gullies it moves soil and rocks with it. Gullies flow together to form a larger channel called a stream More about Gullies •A channel along which water is continually flowing down a slope •Small streams are often called creeks or brooks. A Stream Amount of rain an area receives How much vegetation is in an area ◦ Grasses, shrubs, and trees Type of soil in an area Shape of the land How people use the land ◦ Asphalt Factors that Affect Erosion Source: Paul Fuqua Copyright 2003 Pores: Spaces between rocks and soil particles. 2. Permeable: Materials that allow water to easily pass through them. 3. Impermeable: materials that do not allow water to pass through them easily. 4. Saturated Zone: the area of permeable material that is totally filled with water. 1. Water Underground:Definitions Chapter 6 Lesson 3 Water Table:the area above the saturated zone. 6. Unsaturated zone: the layer above the water table. 7. Aquifer: Any underground layer of rock and sediment that holds water. 5. Definitions Continued Springs: Areas where the water table meets the ground surface. 9. Recharge: New water that enters an aquifer from the surface. 10. Artesian Wells: A well in which water rises because of pressure within the aquifer. 8. Definitions Continued http://www.gov.pe.ca/photos/sites/environment/groundwa ter_e.jpg?3432 Water falling over a waterfall or dam can be channeled to turn large turbines. These turbines contain large magnets. The spinning of the magnets produces electricity that can be sent out through wires to homes and businesses. This is a renewable energy source that is non polluting Hydroelectric Power Building a dam is expensive. There are few areas left suitable for building dams. Dams affect living things around them. Building a Dam floods and destroys habitats and farmland, forces people to relocate their homes. They prevent fish like Salmon from swimming to their breeding grounds The Impact of Dams Hydroelectric power is cheap, clean energy once the Dam is built. The lakes created provide for fresh water reservoirs as well as fishing, boating, swimming and other recreation. They supply water for irrigation and help control flooding Benefits of Dams Disease causing organisms Pesticides and fertilizers Industrial Chemicals Metals Radioactive Wastes Petroleum Products. Agents of Water Pollution Chapter 13 Lesson 4 The major sources of water pollution are human wastes, industrial wastes, agricultural chemicals, and runoff from roads. Point source pollution- is a source of pollution that can be specifically identified like a pipe. Non-point source pollution occurs where the source cannot be specifically linked. Point and Non- Point Waste water treatment helps to clean waste water so that it is safe to return to the environment. In Cities however sanitary sewers can overflow during floods allowing untreated waste water to enter fresh water sources. To prevent disease during these times people are told to boil their drinking and cooking water for at least 10 minutes. Human Wastes In Rural areas waste water can also be a problem. People must also be careful to place their septic tanks away from streams, wells, and not on hills where waste water can flow into fresh water sources. Wastes from farm animals an also be a problem in rural areas. Human Wastes Chemicals: Can be released directly into streams and rivers. They can also leak from barrels where they are stored. Smoke and Exhaust: burning of fuels such as coal, and petroleum products can release sulfur and nitrogen oxides into the air when they mix with water vapor in the air, they form strong sulfuric and nitric acids that fall to earth as acid rain. Industrial Wastes Heat pollution: Heated water from industrial manufacturing returned to streams and rivers heats the water to the point where fish and plant life cannot survive. Agricultural Chemicals: Fertilizers that runoff into ponds and lakes can cause an increase in the algae growth that decreases the amount of oxygen and speeds up the eutrophication process. More Industrial Wastes Gasoline, oil and salt from roads can runoff into streams and rivers and can seep into groundwater and cause pollution. Runoff from Roads Living things in Wetlands, lakes and streams filter out and break down waste materials. Bacteria can be helpful in breaking down waste material and petroleum products. Sand and Rock also act as filters to remove larger particles from water entering an aquifer. Cleaning up the Water Encourage the cleanup of point source pollution sites. Encourage laws and restrictions that will force industries to keep the water clean. Farmers can leave reparian buffers along streams and other areas that will help absorb fertilizer and other runoff. Dispose of chemicals and other toxic substances wisely. How can we help? Reparian Buffers http://www.srs.fs.usda.gov/science/images/buffer.png Water Treatment Pearson Science Explorer Textbook Water Treatment Pearson Science Explorer Textbook