The layers of Earth
Which layer of the Earth is the outermost solid layer that we live on?
the Crust
Which sphere includes all the water on Earth (oceans, lakes, rivers, and groundwater)?
Hydrosphere
What are the large pieces of Earth's lithosphere that move on the mantle called?
Tectonic plates
What was Pangaea? (Short definition)
Pangaea was a supercontinent where all the continents were joined together long ago.
Name the hot, flexible layer beneath the lithosphere that allows tectonic plates to move.
Asthenosphere
Which sphere refers to the solid rock and soil of Earth (including the crust and uppermost mantle)?
Lithosphere (or geosphere)
What type of plate boundary occurs when two tectonic plates move away from each other? Give one example feature formed there.
Divergent boundary — forms mid-ocean ridges (example: Mid-Atlantic Ridge)
Name one type of evidence scientists use to support the idea that Pangaea once existed.
Fossil evidence, matching rock layers, or the fit of continent coastlines (any one is correct)
Which sphere includes all living things on Earth? Give one example of an interaction between this sphere and the atmosphere.
Outer core (liquid) — it helps generate Earth's magnetic field
Which sphere includes all living things on Earth? Give one example of an interaction between this sphere and the atmosphere.
Biosphere
What type of boundary happens when two plates collide and one plate is pushed under another? Name a real-world example (continent or ocean region).
Convergent boundary with subduction — example: the Andes mountains (Nazca Plate subducting under South American Plate)
Explain in one sentence how the shapes of continents support the Pangaea idea.
The coastlines of continents like South America and Africa fit together like puzzle pieces, suggesting they were once joined.
Which Earth layer is the densest and located at the very center of the planet? Is it solid or liquid?
Inner core — solid
Which sphere is the layer of gases surrounding Earth? Name two gases that make up most of this sphere.
Atmosphere — mainly nitrogen and oxygen
What is the boundary called when two plates slide past each other horizontally? Name a famous fault associated with this boundary.
Transform boundary — example: San Andreas Fault
Who proposed the idea of continental drift (the precursor to plate tectonics) and suggested continents had once been joined?
Alfred Wegener
Put these layers in order from the surface to the center: outer core, crust, inner core, mantle.
Crust, mantle, outer core, inner core
Explain briefly how the hydrosphere and lithosphere interact to help form a river valley (one or two clear sentences).
Rain (hydrosphere) flows over rocks (lithosphere), eroding them and cutting a valley. / Water wears away rock and moves sediment downhill, forming a river valley
Describe how the movement of tectonic plates can cause earthquakes and volcanic eruptions (two to three sentences, grade-appropriate).
Plate movement causes stress to build where plates meet. When this stress is released suddenly, the ground shakes (earthquake). If one plate is pushed under another (subduction), melting can form magma that rises to the surface and causes volcanoes.
Describe how the breakup of Pangaea is related to the motion of tectonic plates. Include why continents moved apart
Pangaea broke apart because the tectonic plates on which the continents sit moved. Magma movement in the mantle and processes at plate boundaries pushed plates apart (at divergent boundaries) and pulled them in other directions. Over millions of years, this movement separated the single landmass into the continents we have today.