8-3-1 Earthquakes Flashcards
(24 cards)
What causes an earthquake?
Volcanic or magmatic activity and other stress changes in the earth.
What does an earthquake describe?
Sudden slip on a fault and resulting ground shaking and radiated seismic energy.
What causes stress?
Tectonic plate movement.
What does stress cause?
It causes the deformation of rocks.
What are the tectonic plate movements?
Plastic, elastic and elastic rebound.
What tectonic plate movement does NOT cause earthquakes?
Plastic
What tectonic movement stretches the rock then reaches a breaking point, releasing energy?
Elastic
What is the tectonic plate movement wherein deformed rock goes back to its original shape?
Elastic rebound
What are the three types of faults?
Normal, Thrust and Strike-slip.
What are the three kinds of waves?
Primary wave, Secondary wave, Surface wave.
What is the first wave to arrive at an earthquake?
Primary wave
What is the last wave to arrive at an earthquake?
Surface wave
Which wave compresses and expands?
Primary wave
What wave travels through the earth’s surface only?
Surface wave
What wave travels through the crust and upper mantle only?
Secondary waves
What wave can travel at any medium?
Primary wave
What wave is the most destructive and is the slowest?
Surface waves
What wave can be up and down, around and back and forth?
Surface waves
How can scientists calculate how far a location is from the epicenter?
Difference in arrival times between S and P waves
What wave moves the ground up and down or side to side?
Secondary wave
What are the parts of an earthquake?
Focus, Epicenter and fault.
What is the focus?
Point inside the earth where an earthquake begins.
What is the epicenter?
Point of earth’s surface above the focus.
What stress is the cause of the thrust fault?
Compressional stress
