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A break in the crust along which the rocks move
What is a fault?
Type of plate boundary where plates are colliding (India)
What is convergent?
The place on Earth directly above where the earthquake happened
What is the epicenter?
The most destructive of all the earthquake waves, which cause buildings to collapse and poles and pipes to break
What are surface waves?
Describes a volcano that is not a threat to ever erupt again
What is extinct?
Process by which a dense ocean plate gets pushed under a land plate all the way to the mantle
What is subduction?
The process by which brand new ocean floor is made, discovered by Harry Hess
What is sea-floor spreading?
Described by the Richter scale, this is the strength of the shaking in an earthquake
What is magnitude?
The type of stress that acts on rocks at convergent boundaries and reverse faults
What is compression?
An area of mantle away from a plate boundary that is unusually hot and burns through the crust (Hawaii)
What is a hot spot?
An undersea mountain range, such as the one in the center of the Atlantic
What is a mid-ocean ridge?
The type of plate boundary where plates are pulling away in opposite directions
What is divergent?
Described by the Mercalli scale, these are the specific effects of the earthquake at the surface
What is intensity?
The stress that acts on rocks at transform boundaries and strike-slip faults
What is shearing?
A large gently sloping volcano that releases liquid lava that builds up over time (Mount Kiluaea)
What is a shield cone volcano?
Type of plate boundary where plates are slipping past each other, like San Andreas
What is transform?
The place inside Earth where the rocks actually snap, producing an earthquake
What is the focus?
Earthquake waves that stress rocks at a right angle to the direction of the wave, arriving second at the seismograph
What are secondary waves?
The type of stress that acts on rocks at divergent plate boundaries and normal faults
What is tension?
Also called a stratovolcano, this type is made of alternating layers of ash and hardened lava (Mount Saint Helens)
What is a composite cone?
Heat currents in the mantle driving the movement of plates
What is convection?
A large ocean wave caused by an underwater earthquake
What is a tsunami?
The fastest of all earthquake waves, and therefore the first to arrive at the seismograph
What are primary waves?
Describes a volcano that has not erupted in more than 200 years, but still could
What is dormant?
A small volcano made only of ash at a new vent in the Earth's surface (Sunset Crater in Arizona)
What is a cinder cone volcano?