Mantle Convection & Plate Tectonics
What causes warm mantle material to rise and cooler mantle material to sink?
Differences in temperature and density.
Which type of plate boundary occurs when two plates slide past each other?
Transform boundary.
What type of plate boundary commonly forms mid-ocean ridges?
Divergent boundary.
What type of rock forms when magma or lava cools and solidifies?
Igneous rock.
Name one gas released during a volcanic eruption.
Carbon dioxide (CO₂), sulfur dioxide (SO₂), or water vapor (H₂O).
How does radioactive decay contribute to plate movement?
Radioactive decay releases internal heat that helps drive mantle convection.
How can earthquake maps help scientists identify active plate boundaries?
Earthquakes often cluster along plate boundaries, revealing where plates interact.
How does continental collision create mountains?
Compression pushes the crust together, causing it to fold, thicken, and rise.
Explain the difference between weathering and erosion.
Weathering breaks down rock in place; erosion moves sediment to another location.
How can volcanic ash affect plants and soil?
Ash can damage plants, but weathered volcanic ash can add minerals to soil over time.
A piece of mantle material heats up and becomes less dense. Predict what happens next and explain why.
It rises because it is less dense than the surrounding material.
Scientists find frequent earthquakes where two plates move apart. Identify the boundary and explain why earthquakes occur there.
Divergent boundary; plates separate, causing rocks to fracture and release energy.
A deep ocean trench forms beside a chain of volcanoes. Explain what plate movement could have created these features.
Subduction at a convergent boundary; one plate sinks beneath another, forming a trench and potentially generating magma that feeds volcanoes.
Water freezes inside a crack in a rock. Explain how repeated freezing and thawing can break the rock apart.
Water expands when it freezes, widening the crack until pieces of rock break off.
Sulfur dioxide is released during a volcanic eruption. Explain how it can contribute to acid rain.
Sulfur dioxide reacts in the atmosphere to form acids that can fall with precipitation.
Explain how differences in temperature and density create a convection current in the mantle.
Warm, less-dense material rises, cools, becomes denser, and sinks, creating a continuous cycle.
An earthquake produces both P waves and S waves. Explain one difference between how these waves travel through Earth.
P waves travel through solids and liquids; S waves travel through solids only.
A fault forms as rocks are pulled apart and one block moves downward. Identify the fault type and explain the forces involved.
Normal fault; tension pulls the rocks apart.
A rock reacts with acid rain, changing the minerals within it. Identify the type of weathering and explain your reasoning.
Chemical weathering because the rock's minerals undergo chemical changes.
A volcanic eruption releases ash and gases and contaminates a nearby lake. Identify three Earth systems affected and explain one effect on each.
Atmosphere: ash and gases reduce air quality. Geosphere: ash and lava alter the land. Hydrosphere: ash and chemicals contaminate lake water.
Earth's internal heat decreases significantly. Predict how this could affect mantle convection and tectonic plate movement over a long period.
Mantle convection would likely slow, potentially slowing tectonic plate movement.
Scientists find a region with frequent earthquakes and volcanic activity. Explain how plate boundary data could help them predict where future events are more likely to occur.
Scientists can identify active plate boundaries and use historical patterns to identify areas more likely to experience future earthquakes and eruptions.
A chain of volcanic islands becomes progressively older in one direction. Explain how a hotspot and plate movement could create this pattern.
A plate moves over a relatively stationary hotspot. New volcanoes form above the hotspot while older volcanoes move away with the plate.
Two hills have the same type of rock, but one is steep and receives heavy rainfall while the other is flat and dry. Predict which hill is likely to experience more erosion and explain why.
The steep, rainy hill because runoff moves downhill more quickly and carries sediment away.
A volcanic eruption creates a new island, releases gases into the atmosphere, and affects nearby marine life. Explain how the eruption affects all four Earth systems.
Atmosphere: gases affect air quality and climate. Geosphere: lava creates new land. Biosphere: organisms may be harmed or habitats changed. Hydrosphere: ash, heat, and chemicals affect ocean water and marine ecosystems.