Changes to the Earth Study Guide Earth has a core, crust, and mantle. The core is made of a solid inner region and a liquid outer region. The mantle is the middle layer of earth made up of molten rock. We live on the Earth s crust. There are 8 major plates that slide on the mantle of the Earth. 1 of 8
When these plates move they cause earthquakes and volcanic eruptions. That is why volcanoes often occur at the edge of a plate. A hot spot is a weak part on the surface of the Earth that can let magma come out and form a volcano. The Hawaiian Islands were formed by a hot spot. The Ring of Fire has many volcanoes as well as earthquake sites, around the edges of the Pacific Ocean. Approximately 90% of A:LL earthquakes occur along the Ring of Fire, and the ring is dotted with 75% of ALL active volcanoes on Earth. The Ring of Fire isn t exactly a circular ring. It is shaped more like a 40,000-kilometer (25,000-mile) horseshoe. A string of 452 volcanoes stretches from the southern tip of South America, along the coast of North America, across the Bering Strait, down through Japan, and into New Zealand. Several active and dormant volcanoes in Antarctica,, close the ring. tionalgeographic.org/encyclopedia/ring-fire/ 2 of 8
The surface of the earth is always changing. Earth changes different ways. Three ways are weathering, erosion, and deposition. These processes are different! DEPOSITION sediment (rocks and soil) are dropped or set down in a place 3 of 8
Be sure you know the difference between these three types of resources and know examples of each one. Landforms Delta - created when sediments are at the mouth of a river. Sediments are left and create small islands that causes the river to break into channels that then flow into the ocean Canyon -Created by Rock that has been carried away by fast moving water. Examples are the Rio Grande river created the Santa Elena Canyon at Big Bend in Texas; the Colorado River created the Grand Canyon in Arizona; the Prairie Dog Town Fork of the Red River created Texas Palo Duro Canyon near Amarillo. Sand Dune -A sand dune is created when wind picks up and carries sand to a new spot and it. 4 of 8
Nonrenewable resources are resources that people will use up before they can be replaced, like fossil fuels and minerals. These resources cannot be replaced in a lifetime. Renewable resources are resources that can be replaced in a short amount of time (a lifetime) or are continually replenished, such as: Renewable resources can be ruined by pollution! 5 of 8
Alternative Energy sources are renewable. The Earth is able to replenish them within our lifetime. We need to find ways to use these resources more. The alternative energy sources are: hydropower, wind, solar, biomass, and geothermal. In order to make electricity using hydropower, wind, and geothermal energy is transferred by moving a turbine which moves a generator that creates electrical energy. Biomass like wood, corn, waste material can be burned to create heat. Biomass can also be put into huge tanks that create biogas as they decompose. This biogas can be used to create heat and light homes. Corn can also be turned into a liquid fuel called Ethanol that people can use to run an engine. Wind Energy is caused by the uneven heating of the Earth (since the Earth is tilted, different parts get more/less direct sunlight). We can capture wind energy using a turbine. Geothermal Energy comes from deep inside the Earth s crust. The areas of the crust closer to the mantle are extremely hot. Sometimes the crust is not as thick and the mantle (magma) is closer to Earth s surface. This area of the crust is thin enough that we can run pipes through this area of hot rocks and hot underground water reservoirs. The 6 of 8
water we pump through in the pipes gets heated by the rocks, turns into steam, and can be used to turn a turbine and create electricity. Hydroelectric (hydro=water) power created from running water Advantages to hydroelectric power: Fuel is not burned so there is minimal pollution Water to run the power plant is provided free by nature Hydropower plays a major role in reducing greenhouse gas emissions Relatively low operations and maintenance costs The technology is reliable and proven over time It's renewable - rainfall renews the water in the reservoir, so the fuel is almost always there Disadvantages to hydroelectric power: High investment costs Hydrology dependent (precipitation) In some cases, inundation of land and wildlife habitat In some cases, loss or modification of fish habitat Fish entrainment or passage restriction In some cases, changes in reservoir and stream water quality In some cases, displacement of local populations Solar Energy Solar power is energy from the sun that is converted into thermal or electrical energy. Solar energy is the cleanest and most abundant renewable energy source available Energy Sources 7 of 8
There are 6 main energy sources from which we get all of our energy Non Renewable ----Fossil Fuels (coal, oil, natural gas) Renewable ------Hydropower, Wind, Solar, Geothermal, Biomass Fossil Fuels (like coal, oil, and natural gas) are nonrenewable. There is a limited supply. It takes the Earth of years to create them. We need to start conserving these resources or they will run out. We mostly use fossil fuels. Fossils Evidence of what life was once like. 8 of 8