Measures the earthquake's magnitude
The crust and upper mantle
The beginning point of an earthquake
Vibrations of energy that flow from the focus of an earthquake
Occurs when rocks move apart, forming a gap
An avalanche-like emission of red-hot dust and gases from a volcanic eruption
Area around the Pacific Ocean where many volcanoes and earthquakes occur
What causes an earthquake?
The strength of the seismic waves
Breaks in the earth's crust where rocks can move
Volcanic Fog
Occurs when rocks move horizontally past each other
Which volcano is expected to erupt again within the next five years and has a bowl-like crater at its top?
The point on the earth's surface directly above the focus
Which volcano has mild eruptions and is gradually sloping with a continuous flow of lava?
Occurs when part of a mountain collapses, causing mud and rock fragments to surge down the mountain
Occurs where water is heated by hot magma
Magma that breaks through the earth's surface
Slow, destructive waves that occur on the earth's surface
Detects, times, and measures the movements of the earth
What causes a volcano to erupt
Fast-moving waves that occur beneath the surface of the earth
Which volcano is presently inactive and seems to be layered, showing that different types of lava flows have happened in the past?
The idea that the earth's crust is made of moving plates of land
Occurs when rocks push together, forcing a section of rock upward
