- boundary where two plates are moving toward each other
core
- central part of the earth made of iron and nickel
crust
- outer solid portion of the earth from 5 - 30 miles deep
D
divergent boundary
- boundary between two plates that are moving apart
E
earthquake
- sudden, rapid shaking of the earth's crust caused by moving tectonic plates
epicenter
- a location on the earth's surface directly above the earthquake's focus
F
fault
- the place where tectonic plates meet or come together
fault scarp
- A fault scarp is a small step-like offset of the ground surface in which one side of a fault has shifted vertically in relation to the other
foci
- plural form of the word focus
focus
- a location inside the earth where the earthquake takes place
G
geologist
- scientist who studies the earth
H
hazard
- danger
hypocenter
- The point within the earth where an earthquake rupture begins, also known as the focus
I
intensity
- strength
L
liquefaction
- during an earthquake, solid surfaces can react like liquids
M
magnitude
- the amount of energy released from an earthquake
mantle
- the melted layer of the earth just below the crust
Mercalli Intensity Scale
- a method of measuring earthquakes based on visual observation - uses a scale of 1-12
P
P waves
- primary or first waves of an earthquake that move longitudinally
plate margin
- the area where two tectonic plates meet
R
Richter Scale
- a method of measuring earthquakes based on seismographic readings
Ring of Fire
- an active zone around the pacific ocean where plates of oceanic crust slip under the continental crusts - 4 out of 5 earthquakes take place along the pacific ring of fire - a huge number of volcanoes lie in the area too
S
S waves
- secondary waves of an earthquake which move up and down; these arrive slower than P-waves
seismogram
- the paper output from a seismograph machine
seismograph
- a sensitive piece of equipment used to measure and determine intensity of earthquakes
seismologist
- a scientist - sometimes a geologist - whose study pertains to earthquakes
seismology
- the science of using readings from a seismograph to determine intensity of earthquakes
shockwave
- waves of energy that travel through the Earth's layers as a result of an earthquake; also known as seismic waves
T
tectonic plates
- huge sections of the earth's surface that float on the mantle
transform plate boundary
- boundary where two plates are moving past each other
tremors
- the shaking or trembling of the earth is sometimes called a tremor; another word for earthquake
tsunami
- a huge wave caused by sudden movement of the earth's surface - usually related to an earthquake or volcano
V
volcano
- an opening in the earth's crust through which molten rock and gases are released
