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SEPUP UNIT D: PLATE TECTONICS
Study guide
1. Define the following terms:
Geologists
Scientists who studies rocks, minerals, and other nonliving parts of the earth
Geological time Time periods of thousands, millions, and billions of
years
Pangaea
A super continent that existed until about 230 million
years ago when it began to move apart
Continental
Drift
The idea that continents are moving away from each
other
Transform
boundary
Two plates sliding past each other
Divergent
boundary
Two plates spreading apart
Convergent
boundary
Two plates colliding together
Weathering
Cracking/breaking apart of rocks from wind, water,
ice, plants or animals
Erosion
The transporting of sediment from one place to
another from wind, water, or ice
2. Why would the finding of the same kind of unusual fossils in South
America and Africa provide evidence for plate tectonics? Explain:
Animals live in similar regions. Fossils of these animals supports the idea that these
regions were once similar and therefore were connected at a similar location and time.
3.
a. What is subduction?
Subduction is the sinking of one tectonic plate under another tectonic plate.
b. At what type of plate boundary does subduction occur?
Subduction occurs at a convergent plate boundary with typically two oceanic plates or
An oceanic and continental plate.
4. Why do geologists, or scientists who study the forces and shape of the
earth have such a hard time predicting when earthquakes will occur?
Explain:
Geologists don’t know how much pressure or strain is occurring at each
fault/plate boundary. Without knowing this, predicting plate movement to
Identify the relief of pressure is difficult.
5. Use the circle below to draw a diagram of the earth's interior by:
a. Sketching the approximate size of each layer
b. Labeling each layer with its name and it’s make up (ie: solid, liquid,
solid and liquid)
Lithosphere,
solid
Crust, solid
Mantle,
upper
is solid/
lower
is
liquid
Outer Core,
liquid
Inner
Core, solid
6. In your own words, explain (Be as specific as you can):
a. the theory of plate tectonics
The theory that the surface of the earth is made up of several giant
lithospheric plates that are in constant motion. The plates are moving
Because of convection currents in the mantle beneath the plates.
b. how the use of sonar in World War 2 helped support the theory of
plate tectonics.
The use of sonar allowed for mapping of the ocean floor. It was there that
the discovery of oceanic ridges, mountains, and volcanoes were found.
7. Draw and describe how each of these types of volcanoes are created
Shield volcano: Large, broad
Cinder Cone volcano: Smallest of the
Volcanoes. Formed by releasing
Volcanoes. Formed from explosive
Fast moving, less gassy lava which
Eruptions that shoot magma/ash into
is less explosive.
The air. This falls back down and
forms the cinder cone shape.
Composite volcano: Explosive
eruptions because of gassy magma.
They are formed from alternating
layers of lava, cinders and ash.