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Glossary
- Convection Currents
- Warm material in a fluid rises towards the surface, cools, and then
descends again to be reheated. You can see this in a boiling pot of
water - it also happens in the mantle of the Earth on a much longer
time scale.
- Convergent Boundary
- A plate boundary where two plates are moving towards each other forcing
either subduction, collision, or lateral movement.
- Divergent Boundary
- A plate boundary where new crust is being created as the old crust
on each side moves away as if on a conveyor belt.
- Epicenter
- An epicenter is the spot on the Earth's surface directly above the
underground focus of the earthquake.
- Faults
- Faults are fractures in rocks where movement has occured.
- Fault Zones
- Areas of many closely-spaced faults.
- Focus
- The actual location within the crust where the earthquake occurs.
Compare to 'epicenter'.
- Geophysics
- Study of the Earth using quantitative phsyical methods (seismology,
tectonics, geological engineering, for example).
- Qualitative
- A rough or incomplete observation of a process or object. 'Earthquake
A was stronger than earthquake B because it did more damage.'
- Quantitative
- Placing real numbers or constraints on a qualitative observation.
'Earthquake A released 10 times as much energy as quake B and was a
7.4 on the Richter scale.'
- Radioative Decay
- The natural, spontaneous disintegration of unstable atoms. This process
release heat energy.
- Seismology
- The study of earthquakes and the interior of the Earth.
- Strain
- The change in the shape or size of an object when it is deformed by
stress.
- Stress
- The external pressure acting on an object.
- Strike-slip Fault
- The word 'strike' here refers to the compass direction of the trace
of the fault on the Earth's surface. Thus a 'strike-slip' fault has
its 'slip' or movement in the same direction as its 'strike' - in other
words largely horizontal movement.
- Subduction Zone
- A plate tectonic setting where one plate in a convergent boundary
is forced down beneath the other and is said to be 'subducted' back
into the mantle. A subduction zone usually is marked by a trench on
the sea floor.
- Tectonics
- Processes that deform the Earth's crust.
- Transform Fault
- A special kind of 'strike-slip' fault that involves horizontal offset
of a spreading center or ridge.
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