Plate Tectonics Worksheet

Define plate

• rigid pieces of the lithosphere that floats on top of the asthenosphere in the mantle

• convection currents that are responsible for continental drift

• formed at two convergent boundaries

• formed at two divergent boundaries

Define Theory of Plate Tectonics

• Earth's surface is made of rigid slabs of rock/plates that move with respect to each other

• the continents were moving 180 million years ago, but has since stopped

• Pangea broke apart due to the same asteroid that wiped out the dinosaurs

• the process that creates and destroys the rock cycle

Which is evidence used by Alfred Wegener to support his hypothesis

• Fossil clues

• Rock clues

• Continents fit together like puzzle pieces

• More than one correct answer

Define asthenosphere

• rocky

• plastic-like layer at the upper mantle upon which the plates rest

• the layer that is more dense

• the layer that is least dense

Because granite ______ dense compared to basalt, continents _______ the lithosphere

• is more; sink under the

• is less; sink under the

• is more; float on the

• is less; float on the

The lithosphere is ______ but is broken into ________.

• hot; pieces

• cold; pieces

• solid; pieces

• liquid; pieces

Why do earthquakes (and volcanoes) occur at plate boundaries?

• because the core is constantly spinning and it causes the plates to shake constantly

• the earth is spinning and sometimes it spins too fast creating an earthquake

• stress builds up and when the breaking point is reached, the energy released creates earthquakes

• there are a lot of people living on/near plate boundaries; when those people jump up and down it creates an earthquake

what is the pattern of magnetic polarity reversal?

• every few hundred years to few thousand years

• every few hundred thousand to few million years

• every few ten thousand years

• every few billion years

How are plates moving at divergent boundaries

• north

• parallel

• apart

• together

Give and example of a sliding (transform) boundary

• Hawaii

• Mt. Hellen

• San Andres

• South America