Volcanoes
Hot, molten rock beneath the Earth's crust
What is magma?
This type of boundary is where plates scrape or rub against each other. Most earthquakes occur at these types of boundaries.
What is a transform boundary?
The formation of ridges and trenches along the ocean floor from magma oozing out of cracks explains this theory.
What is sea-floor spreading
The name of the supercontinent or large land mass that existed millions of years ago.
What is Pangea?
The point where an earthquake starts.
What is the focus?
A central opening in a volcano through which magma may escape.
What is a vent?
These types of boundaries collide into each other and are where many mountains are formed.
What is a convergent boundary?
Sea-floor spreading occurs at this famous ridge, which was discovered in the 1940's through sonar technology.
What is the Mid-Atlantic Ridge?
This theory was proposed by Alfred Wegener and suggested that continents spread apart over time.
What is the continental drift theory?
These large ocean waves form when an earthquake occurs under the ocean floor.
What is a tsunami?
Volcanoes are more likely to happen here than in the middle of a plate.
What are plate boundaries?
Heat from below the Earth's surface gives off this kind or energy. Humans can use this energy for powering factories and other things.
What is geothermal energy?
Older crust formed by sea-floor spreading is located here.
What is further away from the ridge?
Twisted layers of rock in this layer of the Earth suggests that plates are moving.
What is the crust?
The place where people would first feel an earthquake.
What is an epicenter?
This type of volcano occurs when a lot of gases have escaped from the magma, so the lava is likely to flow or ooze out of the vent.
What is a shield volcano?
A cup-like structure at the opening of a volcano.
What is a crater?
Sea-floor spreading occurs at this type of boundary.
What is a divergent boundary?
Earth's crust is "recycled" by new crust forming and by this process where a denser plate gets pushed beneath a less dense plate and eventually melts into magma.
What is subduction?
The vibration that spreads out away from a focus when an earthquake happens is called this.
What is a seismic wave?
This is not technically a volcano because it shoots out boiling hot water instead of lava, which has built up underground until it finally explodes.
What is a geyser?
This device is used by geologists to detect shaking in the Earth's crust.
What is a seismograph?
Plates move because of the rising and sinking magma. This type of movement is compared to a boiling pot of soup and is this type of current.
What is a convection current?
This idea explains both sea-floor spreading and continental drift theories by stating that the Earth's surface is broken into plates that move.
What is plate tectonics?
The amount of energy released by an earthquake is called this.
What is magnitude?