Waves in which particles of material move back and forth parallel to the direction in which the wave itself moves.
The concept that earthquakes occur when rock elastically bends until it fractures; the fracturing generates earthquake energy and decreases the elastic energy stored in the rock.
A small step on the ground surface where one side of a fault has moved vertically with respect to the other.
The transformation of seemingly solid sediment into a liquid-like slurry, in response to ground shaking.
Any numerical representation of the size of an earthquake as determined by measuring the amplitude of ground motion.
Mercalli intensity scale
An earthquake characterization scale based on the amount of damage that the earthquake causes.
A numerical representation of the size of an earthquake that takes into account the area of the fault that slipped, the amount of slip, and the strength of the rock that broke.
A scale that defines earthquakes on the basis of the amplitude of the largest ground motion recorded on a seismogram.
Seismic waves in which particles of material move back and forth perpendicular to the direction in which the wave itself moves.
Stop-start movement along a fault plane caused by friction, which prevents movement until stress builds up sufficiently.