8th Grade Earth Science Study Guide
1.
Where’s is most of Earth’s water located? Oceans
2.
What are meteorologists? Someone who studies weather events
3. What are air masses? Fronts? Air masses are large bodies of air, fronts are the area between air
masses
4.
What are droughts? Stretch of time with very limited amount of precipitation
5.
What are tornados? Spinning column of air which stretches from the cloud to the ground.
6.
Where do climate conditions cause hurricanes to become larger and more powerful? Climate
conditions which are warm allows for more strength.
7.
Which contributes to the formation of hurricanes during the late summer? Warm climate over
warm bodies of water (sea water)
8. What would happen if fertilizer would runoff into a lake? Pollutes the lake, animals/plants get
sick /die
What would happen to the water? It is polluted and unfit for life
9. Where does water vapor come from in the atmosphere? From evaporation of water on Earth
10. ¾ of Earth’s surface is covered by water. Which of these describes nearly 97% of the water on
Earth’s surface? Salt water
11. Where is most of Earth’s freshwater? Frozen
12. Which technology best monitors temperature changes in Earth’s ocean? Tsunami buoys
13. Humans throughout the world compete with other organisms for water resources. Why would
restricting irrigation be a good way to manage water resources and allow all components of the
environment to share them? If we restrict irrigation this will leave water ways available for all
organisms. (Irrigation closes up water and sends it through pipes for crop use.)
14. Why are industrial factors a major source of air pollution created by humans? Industries burn
natural resources and release pollution into the environment.
15. What is an earthquake? What piece of technology is used to measure earthquakes? An
earthquake is any movement of the lithosphere plates. Seismographs (seismometers) are the
technology used to measure earthquakes.
16. Why would an uplifted mountain be a feature most likely formed at converging continental
tectonic plate boundaries? When plates are converging they are moving together. As these
plates move together they begin to build upward and can form mountains.
17. Why would a volcanic island arc be a landform most likely created when two oceanic plates
converge? When plates are converging they are moving toward each other. When this
happens, on plate can be pushed under the other. The plate pushed underground will melt back
into magma and a volcano can be formed.
18. What evidence do we have that the Earth’s continents were once in vastly different positions
than they are today? Pangaea (fossils, rocks, and ancient glacier)
19. Why is sea-floor spreading evidence of plate tectonics? It shows how the plates move apart and
more magma/lava comes up to form new crust. Continues to move older crust further apart.
20. What does the Richter scale measure in regards to earthquake characteristics ( intensity,
magnitude, frequency, or probability)? magnitude
21. What causes the movement of Earth’s tectonic plates (think about the layers of the Earth)? The
convection currents in the mantle
22. What is the convection current? Where does it occur? The flow of a fluid due to density.
Magma in the mantle gets heated by the core and becomes less dense which causes it to be less
dense making it rise up toward the crust. Then when it gets close to the crust, it cools
(becoming more dense) and sinks.
23. Earthquake waves are recorded by seismograph machines. What does an earthquake wave
transmit? Seismic waves transmit energy
24. Two plates composed of rock and similar density meet along a convergent boundary. What will
happen where the two plates meet? Mountain building
25. What happens at the mid-ocean ridge? Sea-floor spreading (divergent boundary) magma comes
up creating new mountain ranges
26. Why do earthquakes tell scientists about the history of the planet? Shows how the land/plates
have moved. Shows how land forms can be created or destroyed.
27. What are Earth’s four spheres? Hydrosphere, biosphere, geosphere, atmosphere
28. What is included in the atmosphere? Biosphere? Geosphere? Hydrosphere? Air, life, rock, water
(in order of the questions)
29. Which scale is used to determine the strength of a tornado? Fujita Scale
30. Which two elements primarily make up the atmosphere? Nitrogen(78%) and Oxygen(21%)
31. What happens to the Earth’s pressure and temperature as you move from the crust to the core?
As you move deeper the pressure and the temperature increases.
32. What is Pangaea? Supercontinent which existed about 250 million years ago.
33. What is subduction? When one tectonic plate is forced under another plate due to convergent
boundary. One plate is less dense than the other. The plate which is more dense will be pushed
under the less dense plate.
34. Why do earthquakes occur more frequently in California than Kentucky? California is on a plate
boundary between two plates and Kentucky is not.
35. How do natural disasters interact with Earth’s spheres? Be prepared to answer about how a
tornado, flood, hurricane, etc. can impact the four spheres.