20 terms

Earthquakes and Earth Layers.

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Seismic Wave
Earthquake generated waves which travel through the earth
Core
Center of Earth. Outer: liquid metal, Inner: solid metal.
Crust
The outermost layer of the Earth. Contains the asthenosphere and part of the lithosphere. Some regions are more solid than others (Below the asthenosphere).
Mantle
Middle layer of the earth. Contains the asthenosphere and part of the lithosphere. Some regions are more solid than others (below the asthenosphere).
Oceanic crust
Made of basalt. Located BELOW oceans. More dense. Thinner than continental crust.
Continental crust
Made of granite rock. Located below continents. Less dense than oceanic crust, but thicker.
Normal fault
Caused by tension forces pulling rocks apart. Rock above fault surface moves downward.
Strike-slip fault
Caused by shear forces pushing the rocks past each other.
Reverse fault
Caused by compression forces pushing from opposite directions that force rock above the fault up and over rock below the fault.
Magnitude
A measure of the energy released by an earthquake (Richter scale, quantitative)
Richter scale
Used to describe the strength of an earthquake and is based on the HEIGHT of the lines on the seismogram (quantitative data)
Seismograph
An instrument which measures seismic waves from earthquakes. Registers waves onto a seismogram (contains the zigzaggy lines) which shows an earthquakes magnitude.
Focus
The point where energy release first occurs UNDER earth's surface.
Epicenter
The point ON earth's surface directly above the earthquakes focus. Place where EQ is first felt/detected on Earth.
Primary Wave (p-wave)
Causes particles in rock to move back and forth in the same/parallel direction the wave is traveling. Fastest of seismic waves. Move like a slinky
Secondary wave (s-wave)
Cause particles in rock to move at right angles (perpendicular) to the direction the wave is traveling. Second fastest seismic wave. Stopped by liquid. Move like a whipped rope.
Surface waves
Most destructive waves which moves rock in a backward, rolling motion and side to side. Produced when the EQ energy reaches the Earth's surface.
Tsunami
Ocean waves caused by earthquakes that happen under the water.
Liquefaction
When wet soil is shaken by an EQ and causes it to act more like a liquid.
Density
Mass divided by Volume; how much matter is packed inside a certain volume.