Key Terms Volcanoes
Key Terms Earthquakes
Volcanoes Again
What do you know?
Type of volcano
100
Hot molten rock below the Earth’s surface
Magma
100
a vibration that spreads out away from a focus when an earthquake happens
seimic waves
100
What happens when a volcano erupts?
Magma is pushed to the surface because of expanding gases . The magma from the magma chamber moves through the pipe until it flows or explodes out of the vent.
100
magma that reaches Earth’s surface and flows out of a vent
lava
100
shield volcano
200
the central opening of a volcanic area through which magma may escape
vent
200
the point where an earthquake starts as rocks begin to slide past each other
fault
200
What are the three types of wave associated with earthquakes? Which one causes the most damage to the structures on the surface of the Earth?
P-waves, s-waves, surface waves -Surface are most destructive
200
volcano no longer has magma chamber with magma, won’t erupt again
Extinct volcano
200
a wide, gently sloped cone that forms from flows of lava
shield volcano
300
a cuplike hollow that forms at the top of a volcano around a vent.
crater
300
a sensitive device that detects the shaking of Earth’s crust during an earthquake
seimograph
300
What are the types of stress at each boundary?
Transform boundary -
Divergent boundary -
Convergent boundary -
Transform boundary - shearing
Divergent boundary - tension
Convergent boundary - compression
300
volcano may erupt again but is not currently active
dormant volcano
300
a steep-sided cone that forms from explosive eruptions of hot rocks, ranging from particles to boulders
cinder cone volcano
400
What are the four main parts of a volcano?
Magma chamber, pipe, vent and crater
400
the idea that Earth’s surface is broken into plates that move
Theory of Plate Tectonics
400
What are the benefits and dangers of living near a volcano?
benefits - geothermal energy, fertile soil, igneous rock
Dangers - lava flows, toxic gases, fires, earthquakes
400
actively erupting or showing signs of erupting soon, like spitting ash or minor earthquakes
Active Volcano
400
a cone formed from explosive eruptions of hot rocks, ash and cinders followed by a flow of lava, over and over
composite (stratovolcano)
500
convection current heat from below Earth’s surface, may cause geysers or hot springs
geothermal activity
500
a huge ocean wave caused by the seismic waves of an undersea earthquake
tsunami
500
Explain how the convection current in the mantle causes earthquakes and volcanoes.
Convection current provides the energy that powers earthquakes and volcanoes. Magma is molten rock from the mantle. Boundaries are weak spots in the crust, this is where most of the earthquakes and volcanoes occur.
500
What evidence supports the theory of sea-floor spreading?
Newer ocean floor is near the ridge and older ocean floor is farther away from the ridge, magnetic strips in the rock are the same on both sides of the ridges, eruption of molten materials from the mid-ocean ridge.
500
What are the two main types of volcanic eruptions?
pyroclastic (explosive) and quiet eruptions