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Plate Tectonics, Earthquakes, Volcanoes, and Rocks
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Plate Tectonics, Earthquakes, Volcanoes, and Rocks
Plate Tectonics, Earthquakes, Volcanoes, and Rocks
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1
Question
Which three observations support the theory of continental drift?
Page 1
Answer
Matching fossils on different continents, matching glacial evidence on different continents, and continents fitting together like puzzle pieces.
2
Question
How do convection currents move tectonic plates?
Page 1
Answer
They move tectonic plates toward and away from one another, functioning like a conveyor belt.
3
Question
Which evidence shows that new oceanic crust forms at mid-ocean ridges?
Page 1
Answer
Sediment is thinner near a mid-ocean ridge, the sea floor becomes older farther from the ridge, and matching magnetic strips occur on both sides.
4
Question
How does subduction contribute to the formation of geological features?
Page 1
Answer
A denser oceanic plate is pulled beneath a lighter continental plate and sinks into the Earth’s mantle, producing subduction-related features.
5
Question
How do the three main plate-boundary types differ?
Page 1
Answer
Convergent boundaries move together, divergent boundaries move apart, and transform boundaries slide past one another.
6
Question
Who presented the theory of continental drift?
Page 1
Answer
Alfred Wegener.
7
Question
Which ancient supercontinent existed millions of years ago?
Page 1
Answer
Pangea was the supercontinent that existed millions of years ago.
8
Question
How did Laurasia and Gondwana relate to Pangea?
Page 1
Answer
Laurasia was the top part of Pangea after it split, whereas Gondwana was the bottom part.
9
Question
How does heating affect material in a mantle convection current?
Page 1
Answer
Hot material rises and cools as it moves away from and toward a heat source.
10
Question
Which features are associated with convergent destructive boundaries?
Page 1
Answer
Mountains form at convergent destructive boundaries.
11
Question
Which landforms commonly form at convergent subduction boundaries?
Page 1
Answer
Trenches and volcanoes form at convergent subduction boundaries.
12
Question
Which landforms are associated with divergent boundaries?
Page 1
Answer
Mid-ocean ridges, rift valleys, and underwater volcanoes are associated with divergent boundaries.
13
Question
Which geological activity is associated with transform boundaries?
Page 1
Answer
Fault lines and earthquakes are associated with transform boundaries.
14
Question
Why do volcanoes generally occur at subduction plate boundaries?
Page 1
Answer
The melted plate forms explosive magma that travels upward.
15
Question
How can a hotspot below the crust produce a volcano?
Page 2
Answer
A weak spot can form in the crust, especially near an ocean ridge. Very hot magma weakens the area further and pushes through the weak spot.
16
Question
Which four structures should be identified on a volcano diagram?
Page 2
Answer
The magma chamber, central vent, crater, and lava should be identified.
17
Question
How does a stratovolcano differ in structure and lava movement?
Page 2
Answer
A stratovolcano has steep layers of lava and ash and produces stiff, slow-moving lava. It is mostly found at convergent plate boundaries.
18
Question
How does a shield volcano differ from a stratovolcano?
Page 2
Answer
A shield volcano has thinner magma, is less steep, and erupts frequently but less violently. It is found at divergent plate boundaries.
19
Question
Which lava characteristics are associated with a cinder cone?
Page 2
Answer
A cinder cone has the runniest lava, is not steep, has one lava vent, and forms from layers of cinder and ash.
20
Question
How do earthquakes form from tectonic movement?
Page 2
Answer
When two plates fault, they displace the land and send destructive waves of energy in all directions. Subduction boundaries produce the strongest earthquakes.
21
Question
Which plate boundaries produce the strongest earthquakes?
Page 2
Answer
Subduction plate boundaries produce the strongest earthquakes.
22
Question
Where does the source material place the epicentre of an earthquake?
Page 2
Answer
The epicentre is described as the place where the earthquake starts underground.
23
Question
Where does the source material place the focus of an earthquake?
Page 2
Answer
The focus is described as the point directly above the underground start on the surface.
24
Question
How do P waves and S waves differ in motion and speed?
Page 2
Answer
P waves are longitudinal and travel quickly. S waves are transverse, move more slowly, and are more destructive.
25
Question
How do P waves and S waves behave underground?
Page 2
Answer
Both travel deep underground and bend upward toward the surface.
26
Question
Why can earthquake forces be especially damaging to buildings?
Page 2
Answer
Earthquakes make buildings move horizontally, applying a force that is very difficult to counteract.
27
Question
Which structural systems can help buildings withstand earthquakes?
Page 2
Answer
Moment frames, braced frames, damped frames, shear walls, base isolation, and active control systems can help buildings withstand earthquakes.
28
Question
How does an underwater earthquake initiate a tsunami?
Page 2
Answer
It displaces seawater and sends out many short, fast waves of water.
29
Question
Why does a tsunami become higher near shallow water?
Page 2
Answer
The waves slow down without losing energy, allowing waves behind them to catch up and heighten the crest into a giant wave.
30
Question
Which three observations can warn of an approaching tsunami?
Page 3
Answer
Water rushing out into the ocean, the Earth beginning to shake, and an unusual rushing sound are warning signs.