earthquakes
Breaks in earth's surface along which rocks can move
faults
A scientist who studies the movements of the earth
seismologist
A volcano forms where a ________ in the earth's crust allows magma and gases to come to the surface.
crack
Name for the gases released by a volcano
dog
A volcano that does not have a recorded eruption and is not expected to erupt
extinct
An earthquake happens when rocks along plate boundaries shift suddenly and released their _____________.
stored energy
A series of giant ocean waves sometimes caused by an earthquake
tsunami
Two thirds of active volcanoes take place in this location around the edges of the Pacific Ocean
Ring of Fire
Occurs when part of a mountain collapses and mud and rock fragments surge down the mountain
Debris flow
tephra
The beginning point of an earthquake
focus
Type of fault where rocks push together until they force a section of rock upward
thrust or reverse fault
When hot molten rock breaks the surface it is called
lava
This main type of rock is formed as magma and lava cool and harden
igneous
The scale which measures the strength of the seismic waves of an earthquake
Richter
A machine scientists use to detect, time, and measure the movements of the earth
seismograph
The point on the surface of the earth directly above the focus
The bowl shape at the top of a main vent of a volcano is called a
crater
Type of igneous rock that is a combination of 4 different minerals and is used in buildings and monuments
granite
Name for the part of earth which includes the crust and upper mantle; in large pieces called plates.
lithosphere
The slowest and most destructive waves are
surface waves
Two types of surface waves are Rayleigh and _______.
Love waves
Type of volcano with steep sides made of layers of hardened lava and a mixture of ashes, cinders and rock
composite cone
This igneous rock cools quickly and has a shiny surface. It has sharp edges when it breaks and was used for arrowheads and cutting tools.
obsidian
Word for the strength of a seismic waves
magnitude