Crust, Volcanoes, Earthquakes and Plates Flashcards
Oceanic crust is made out of
Basalt
Continental crust is made out of
Granite
Oceanic crust covers about _____ of earths surface
2/3
Which type of crust is thicker?
Continental
Most of earths mass is in the…
Mantle
Mantle is mainly composed of
Iron, magnesium and aluminum
Core is mostly composed of…
Iron
Continental drift theory factors (2)
- ) The continents fit together like a puzzle
2. ) similarities in rocks in the east coasts of north and South America and west coasts of Africa and Europe
The lithosphere contains
The crust and upper mantle
Subduction zones
Where two tectonic plates meet and move toward each other, with one sliding underneath and other moving downwards
Transform boundaries
Plates slide past each other, the friction from the sliding plates frequently starts earthquakes
The San Andreas Fault
Where the pacific and North American plates slide past each other
Divergent boundaries
Two plates slide apart from each other
Convergent boundaries
Two plates slide towards each other, either forming a subduction zone or mountains
Focus
Area where energy is released before an earthquake
Epicenter
Directly above the focus
Richter scale
Strength and magnitude of an earthquake
Body waves and the types
- Travel through the interior of the earth
- Type P and S
P waves
Travel through the Earth and are caused by expansion and contraction of bedrock
S waves
Travel only within the uppermost layers of Earth
Surface waves
Produce swaying motion and are SLOWER than P or S waves. This is what causes ground motion and damage
Severity of an earthquake depends on… (3)
- ) how far below the surface the movement occurred
- ) the amount of potential energy that had been stored
- ) the distance the rock mass moved when the energy was released
Subduction zone related earthquakes generate…
The majority of all tsunamis
Majority of volcanoes occur at…
Subduction zones and mid-oceanic ridges (95%)
Gases released from volcanic eruption
-Carbon dioxide, hydrogen chloride
