Earth Systems
What are the four main spheres of Earths systems?
Atmosphere, hydrosphere, geosphere, and biosphere.
What type of force builds up mountains and other landforms?
Constructive forces.
What are the three main layers of Earth?
Crust, mantle, and core.
What type of waves do scientists study to learn about Earths interior?
Seismic waves
What are the three types of heat transfer?
Radiation, conduction, and convection.
Which sphere includes all of Earth’s water?
The hydrosphere
What is the process that breaks rock into smaller pieces?
Weathering
Which layer is Earths thin, solid outer layer?
The crust.
What are the two main types of evidence scientists use to study Earth’s interior?
Direct evidence from rock samples and indirect evidence from seismic waves
What type of heat transfer occurs when two objects touch?
Conduction.
Which sphere includes all living organisms, including humans, plants, and animals?
The Biosphere
What is the difference between weathering and erosion?
What is the difference between weathering and erosion?
Which layer is made mostly of hot, solid rock and is nearly 3,000 km thick?
The mantle
Why are seismic waves considered indirect evidence of Earth’s interior?
Scientists cannot directly see most of Earth’s interior. Instead, they study how seismic waves travel through Earth to infer what the interior is like.
Why does warm material rise during convection?
Heating makes material less dense, so it rises. Cooler material is more dense, so it sinks.
Explain how a change in one Earth sphere can affect another sphere. Give an example.
The spheres interact because a change in one can affect another. For example, melting glaciers (hydrosphere) can expose or change land (geosphere) and can be affected by warmer air (atmosphere).
Explain how constructive and destructive forces work against each other to change Earths surface.
Constructive forces build up Earth’s surface, such as when volcanoes create new rock or mountains form. Destructive forces wear down Earth’s surface through weathering and erosion.
Compare the outer core and inner core. How are they different?
The outer core is liquid, while the inner core is solid. Both are made mostly of metals, especially iron and nickel.
How can scientists use the way seismic waves travel through Earth to learn about what is inside Earth?
Seismic waves travel at different speeds and follow different paths depending on the material they pass through. Changes in their speed and paths provide clues about different layers and materials inside Earth.
Describe the complete cycle of a convection current, including what happens to temperature and density.
Heat warms material → it becomes less dense → it rises → it cools → it becomes more dense → it sinks → it is heated again → the cycle repeats.
A glacier melts, changing the land around it and adding water to the ocean. Which Earth spheres are involved, and how do they interact?
The hydrosphere (glacier/ocean), geosphere (land), and atmosphere (climate/temperature) interact. Melting changes the amount of water and can change the surrounding land.
A mountain is built by plate movement but later becomes smaller because of rain, ice, and wind. Explain the constructive and destructive processes involved.
Plate movement can build a mountain (constructive), while rain, ice, wind, and changing temperatures can break down and carry away the rock (destructive).
Put these layers in order from Earths surface to its center: inner core, mantle, crust, outer core. Then identify which are solid and which is liquid.
Scientists cannot travel to most of Earth’s interior. Explain how rock samples, seismic waves, and other observations allow scientists to construct a model of Earth’s interior.
Scientists combine direct evidence, such as rocks obtained from drilling and volcanic activity, with indirect evidence, especially seismic waves. By studying how seismic waves behave as they travel through Earth, scientists can determine that Earth has different layers with different properties.
Earths mantle has been moving through convection currents for billions of years. Explain what causes these currents and predict what would happen if Earth’s interior eventually cooled completely.
Heat from Earth’s interior causes mantle material to become warmer and less dense, so it rises. Near the surface it cools, becomes denser, and sinks. This repeated rising and sinking creates convection currents. If Earth’s interior eventually cooled enough, there would no longer be enough heat to drive the currents, so they would eventually stop.