Earthquakes

Terms in this set (17)

Earthquake
shaking and vibration at the surface of the earth resulting from underground movement along a fault plane or from volcanic activity
Seismometer
Instrument used to measure horizontal or vertical motion during an earthquake.
Seismograph
The graph of recorded ground movements caused by seismic waves as they move through the Earth.
Seismic waves
vibrations that travel through Earth carrying the energy released during an earthquake
Primary waves
1st wave, P, travels the fastest, back-and-forth waves, move through solids, liquids, and gases
Secondary waves
Shear wave, travels through solids only, slower than P waves but faster than surface. (2nd fastest)
L waves
Surface waves that are last to arrive, slowest, up and down motion, causes the most damage
Shear stress
A stress that distorts a body by pushing parts of a body (in this case the Earth's crust) in opposite directions.
Focus/hypocentre
The point of Earthquake origin within the Lithosphere
Epîcentre
the point on Earth's surface directly above the focus where an earthquake starts
90% of earthquakes
occur at destructive margins
Richter scale
a logarithmic scale of 1 to 10 used to express the energy released by an earthquake
31.6
The increase or decrease in ENERGY RELEASED as you go up or down one point on the Richter scale
10
The increase or decrease in SHAKING AMPLITUDE as you go up or down one point on the Richter scale
Liquefaction
The process by which an earthquake's violent movement suddenly turns loose soil into liquid mud
Mercalli scale
a scale that rates earthquakes according to their intensity and how much damage they cause at a particular place
Intraplate earthquakes
Earthquakes that occur away from plate boundaries
YOU MIGHT ALSO LIKE...
;