Earthquake terms
Basic terms as related to the study of earthquakes
Terms
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- crest
- the top of a wave is called a
- Fault
- a fracture along which blocks of crust on either side have moved relative to one another parallel to the fracture, a break in the earth's crust
- compression
- the force that squeezes
- Magnitude
- A number that characterizes the relative size of energy of an earthquake.
- Mercalli Scale
- The SCALE that uses the intensity number a number (written as a Roman numeral) describing the severity of an earthquake in terms of damages (people and buildings)
- After shock
- Earthquakes that follow the largest shock of an earthquake sequence. They are smaller than the mainshock
- Reverse fault
- If rock above the fault moves upward, caused by compression forces
- Focus
- the point within the earth ( in the ground) where an earthquake rupture starts
- Earthquake
- vibrations produced when rocks are bent and broken
- Primary Wave
- First seismic wave,or longitudinal wave, is a seismic wave that shakes the ground back and forth in the same and opposite driection the wave is moving
- Epicenter
- The point on the earth's surface vertically above the focus, point in the crust where a seismic rupture begins.
- Surface Wave
- a seismic wave that is trapped near the surface of the earth. Also called a Rayleigh or Love wave.
- Intensity
- A number (written as a Roman numeral) describing the severity of an earthquake in terms of its damage to earth's surface and on humans and their structures (In the Mercalli Scale)
- amplitude
- the height measured for a wave is called the
- Secondary Wave
- Second seismic wave,(transverse wave) is a seismic body wave that shakes the ground back and forth perpendicular to the direction the wave is moving. Also called a shear wave.
- wave length
- the distance between two wave crests is called a
- Liquefaction
- During an earthquake a process by which water-saturated sediment temporarily loses strength and acts as a fluid
- Seismologist
- A person who studies earthquakes
- Seismic wave
- waves (energy) produced by earthquakes starting at the epicenter
- tension
- the force that causes stretching
- Shadow Zone
- This area is a result of S waves being stopped entirely by the liquid core and P waves being bent (refracted) by the liquid core.
- Normal fault
- A rock mass above a fault that moves down during an earthquake, caused by tension forces
- Tremor
- Shaking of the earth before,during and after an earthquake
- Tsunami
- a sea wave of local or distant origin that results from large-scale seafloor displacements associated with large earthquakes, major submarine slides, or exploding volcanic islands
- Strike-slip fault
- vertical fractures where the rocks have mostly moved horizontally, slide past each other
- Seismograph
- is an instrument used to detect and record earthquakes
- trough
- the bottom of a wave is called a