Earth Science Terms
The crust is the outer layer made of rock.
The mantle is the layer of rock beneath the Earth’s crust. It is very hot. Deeper down the mantle is soft, like melted candy. Some of the melted mantle occasionally reaches the Earth’s surface through volcanoes.
The core is the center layer of Earth. It is the hottest layer. There is an outer core of liquid or molten iron. There is also an inner core made of solid iron. Even though the core is very hot, great pressure at the center of Earth keeps the inner core solid.
Source: Harcourt Science, 2000.
Earth Science Notes 2
Tectonic Plates – plates that are solid blocks of crust and upper mantle rock. Most of these plates are larger than continents.
Volcano – a mountain formed by lava and ash.
Lava – magma that has reached the Earth’s surface.
Ash – small pieces of hardened lava.
Magma – hot, soft rock from the Earth’s mantle.
Earthquakes – the shaking of the ground caused by the sudden release of energy in the Earth’s crust.
Faults- breaks in the Earth’s crust that allows the crust to move.
Land Forming – new land can be formed by cooling lava from a volcano.
Mountain Forming – formed as the crust fold, cracks, and bends upward because of movements in the Earth’s plates.
Source: Harcourt Science, 2000.
Earth Science Terms 3
Continental Drift is the theory of how Earth’s continents move over its surface. According to the theory, about 225 million years ago, all of the land on Earth was joined together in one “Supercontinent” called Pangea. Evidence suggests that about 200 million years ago, Pangea broke into two big continents. The southern one is called Gondwana and it contained all the land that is now in the Southern Hemisphere. The northern continent is called Laurasia and it contained North America and Eurasia. Later these continents broke into smaller continents. Today the Atlantic Ocean is getting wider and the Pacific Ocean is getting smaller.
Earth Science Terms 4
Constructive Forces – natural forces that build up the earth’s crust. (plates colliding and making mountains, lava cooling and hardening, deposition)
Destructive Forces – natural forces that tear down and destroy earth’s crust. (weathering, erosion, earthquakes, waves, tsunamis)
Natural Resources – useful minerals and other materials that people take from the Earth.(silver, gold, iron, aluminum, forests, soil)
Nonrenewable Resources – take thousands of years to form. They cannot be replaced once they are used up.(aluminum, iron, copper, silver, gold, diamonds, rubies, fossil fuels, soil)
Renewable Resources – a resource that is replace as it is used.(forests)
Reusable Resources – a natural resource that can be used more than once.(water, wind)
Fossil Fuels – coal, natural gas, and petroleum. Formed from the remains of once living organisms. Burning fossil fuels releases energy that came from the sun.
Natural Gas – methane, propane. Used for heating and cooking. Usually it is found with petroleum deep in the ground.
Coal - formed with 4 steps; peat, lignite, bitumen, anthracite. It comes from plants that lived in swamps millions of years ago. This is the most common fossil fuel,
Harcourt Science, 2000
Earth Science Terms 5
Recycling – to reuse something for a completely different purpose than it was originally meant for.
Atmosphere – The layer of air that surrounds Earth.
Air pressure – the weight of air.
Humidity – the amount of water in the air.
Precipitation – water, in any form, falling from the sky.
Evaporation – liquid to gas.
Condensation – gas to liquid.
Local Winds – winds dependant upon changes in temperature.
Prevailing winds – global winds that blow constantly from the same direction.
Climate – the average of all weather conditions through all seasons over a period of time.
Microclimate – The climate of a very small area.
El Nino – short term climate change that occurs every two to ten years.
Greenhouse effect – process by which Earth’s atmosphere absorbs heat.
Global warming – The hypothesized rise in Earth’s average temperature from excess carbon dioxide.
Harcourt, 2000