Stress
A pulling stress force, that tends to stretch rock and cause it to thin in the middle
What is tension?
A break in the rock where surfaces slip past each other
What is a fault?
This is the fastest seismic wave, and will be the first to reach a seismometer
What is a P-Wave?
This is the minimum number of seismic stations needed to find an earthquake's epicenter by triangulation
What is three?
What is an anticline?
A crushing or squeezing stress force
What is compression?
This fault forms when the hanging wall moves down and the footwall moves up, under tension
What is a normal fault?
This is the spot on the surface, above where an earthquake actually occurs underground
What is the earthquake's epicenter?
This device records shaking from seismic waves
What is a seismometer/seismograph?
A type of fold where the vertex faces down, like the letter "U"
What is a syncline?
A stress force where rock is forced in two opposite directions
What is shear?
This fault forms when the hanging wall moves up, and the footwall moves down, under compression
What is a reverse fault?
The area beneath the ground where stressed rock actually breaks or moves
This earthquake scale relies on damage and shaking to rate an earthquake, not the earthquake's energy
What is the Modified Mercalli Scale?
This type of seismic wave moves the second fastest
What is the S-Wave?
This stress force forms normal faults
What is tension?
This fault forms from shear, when the two fault blocks move horizontally past each other
What is a strike-slip fault?
This seismic wave moves the slowest, and is often the most damaging
This scale for measuring earthquakes rates the earthquake's total energy released
What is the Moment Magnitude Scale?
This large, damaging wave can be formed by underwater earthquakes
What is a tsunami?
This stress force forms reverse faults
What is compression?
The fault blocks around a strike-slip fault only move in this directional plane
What is horizontal?
This feature of an earthquake often determines how damaging it will be, regardless of the earthquake's magnitude
What is an earthquake's depth?
A magnitude 7 earthquake would release this many units of energy
What is 10^7 or 10,000,000?
The gap between the arrival times of the P-wave and S-wave at a seismic station is used to calculate what about an earthquake?
What is distance from the seismic station?