Drifting Continents
Plate Tectonics
Forces in Earth's Crust
Seismic Waves
Monitoring Earthquakes
100
Name the supercontinent that existed 300 million years ago when all continents were joined together.
Pangea
100
What do we call breaks in the Earth's crust?
Faults
100
What do we call the force on Earth's crust that can change it's shape or volume?
Stress!
100
How do we define seismic waves?
The vibrations that are similar to sound waves that travel through Earth carrying energy released by an earthquake
100
Name the place where most of the world's earthquakes occur.
HINT! It circles the Pacific Ocean
200
Name the scientist who proposed the theory of drifting continents.
Alfred Wegener
200
What causes the plates to continually move?
Convection currents
200
What type of stress describes pulling on the crust and thinning of rocks?
200
Name the instrument that measures an earthquakes seismic waves
seismograph
200
On a seismograph, more severe earthquakes will have what kind of lines?
higher or greater or larger
300
Name the long chain of underwater mountains
mid-ocean ridges
300
At what boundary do rift valleys form?
Divergent boundary
300
What type of stress causes plates to slip past one another in opposite directions?
300
Name the area beneath Earth's surface where rock begins to break or move.
Focus
300
Name the pattern of lines that record an earthquakes seismic wave activity.
seismogram
400
Name the device used to measure distance using sound waves that helps map the ocean floor.
Sonar
400
At which type of boundary can subduction occur?
Convergent boundary
400
What type of stress squeezes rock until it folds or breaks?
400
Name the scale that measures the magnitude, or size, of an earthquake.
400
Here in Washington, what plate cause most of our earthquakes?
500
Name the process when part of the ocean floor sinks beneath another and back into the mantle - this process has helped form volcanoes!
Subduction
500
At what type of boundary is crust neither created nor destroyed?
500
Name the 3 types of faults!
Normal, Reverse, Strike-Slip
500
Name the type of seismic waves that vibrate side to side and shake structures violently.
S Waves, or Secondary Waves
500
On a seismograph, what part resists motion during an earthquake?
