Natural Resources Lesson 5.3

What are natural resources?  Almost everything people use comes directly or indirectly from natural resources. People need air to breath and water to drink. They need soil to grow food. Rocks and minerals are needed to form soil. Forests produce some of the raw materials for shelter and fuel for fires. Earth’s natural resources can be classified by the time it takes to produce them.

What are fossil fuels?(nonrenewable resources)  Fossil fuels formed from the remains of ancient organisms and is used today as a source of energy.  Sediment covers the dead organsims. The pressure from the sediment presses the dead plants into peat. As peat hardens, it forms a sedimentary rock called bituminous coal, or soft coal.  As bituminous coal sinks deeper into Earth’s layers, it forms a metamorphic rock called anthrocite, or hard coal.  Both hard and soft coal are fossil fuels.

More Fossil Fuels (nonrenewable resources)  When ocean organisms die and sink to the bottom of the ocean, they are also covered by sediment. There, the combination of heat and pressure turned the decayed material into oil or natural gas.  Oil and natural gas can be found under the ocean or under land that was once covered by the ocean.

Using Fossil Fuels (nonrenewable resources)  When fossil fuels are burned, they release the energy stored in the ancient organisms that made them.  Gasoline in a car releases energy to move the engine.  Oil burning releases energy to heat buildings.  Natural gas can be burned on a stovetop to cook food.  Coal, oil, and natural gas can supply energy to a power plant. At the power plant, their energy is converted to electricity, and carried through wires to your home. This power plant uses gas turbines.

More Nonrenewable Resources  Some nonrenewable resources cannot be reproduced at all. They are a fixed quantity. Examples are gold and copper.

Renewable Resources  Nature replaces some resources relatively quickly. These are natural resources.  Wind  Sunlight  Water  Fish  Trees or even dead plants  Animal waste  Some of these come in unlimited supply, like sunlight. Others, like fresh water, exist in limited number even though it’s constantly being replaced. Water shortages can occur if water is polluted or over-used.

Hydro-electric Power Plant

Careful Use of Natural Resources  Trees are not always fully renewable. They are sometimes cut down faster than new ones can grow to replace them. Trees are used for construction of buildings, furniture, and paper, so we need to be careful with this resource.  Animal resources can also be used up quicker than they are replaced. For example, many fish populations are declining rapidly due to overfishing. Once completely gone, a living thing cannot be replaced.

Why is it so salty?  97% of Earth’s water is salty, but why? When rain or snow fall, they fall as fresh water. They land on mountains or other land, then much of it drains to rivers and streams. As it moves across the land, the water picks up sals in soil and rocks. The water then flows into the ocean carrying the salt with it. The salt remains in the ocean. Rivers have salt, but don’t taste salty because it’s such a small amount.

Freshwater Sources  We know that only 3% of Earth’s water is freshwater, and 2% of that is in glaciers. So where is the 1% that we use? It can be found in:  Running water –Many cities are built near rivers and streams. They provide water for homes and businesses. (Pearl River in Jackson)  Standing water- Lakes or reservoirs fill holes in the ground. A reservoir is an artificial lake built to store water. They’re usually built with a dam. (Ross Barnett Reservoir)  Ground water – Seeps into rocks called aquifers. Aquifers have pores that absorb water. Eventually, the water sinks to a rock that will not absorb the water, so it just sits there.

How do we get to the groundwater?  Water is pumped up through a well drilled to reach the groundwater. As water is removed, the level of the water underground drops. In order for the water to reach that height again, more water must seep down to replace it.

How do we clean water? The water pumped into our buildings has been cleaned in a water treatment plant. There, it goes through 5 tanks, each with a different job: 1. Coagulation – Sticky particles are added to the water to attract any dirt in it. 2. Sedimentation- Clumps of dirt and sticky particles fall to the bottom on the tank. 3. Filtration – Water passes through a series of filters, which ar layers of sand, gravel, and charcoal. This removes any remaining particles. 4. Disinfection- Chlorine and other chemicals are added to the water to kill harmful bacteria. 5. Storage – Clean water is stored until needed.