Theory
What was the name of the super-continent when all of the plates were one?
a. Venica b. Pangea c. Crimea
b. Pangea
What are plate boundaries?
a. the middle of tectonic plates
b. the edges of tectonic plates
b. the edges of tectonic plates
What is a volcano?
a. plates slip past each other and waves of energy travel across the earth
b. tectonic plates separate and magma escapes from the mantle.
b. tectonic plates separate and magma escapes from the mantle.
Seafloor spreading happens along a __________ boundary.
a. divergent
b. convergent
c. transform
a. divergent
What are convection currents?
a. circular movements of magma
b. plates crushing together
a. circular movements of magma
Along a ________ boundary, plates crash together. With a _________ boundary, plates pull apart.
a. convergent and divergent
b. divergent and divergent
c. transform and divergent
a. convergent and divergent
Volcanoes form along which two plate boundaries?
a. transform and divergent
b. convergent and divergent
c. transform and convergent
b. convergent and divergent
When two oceanic plates separate and magma is released _____ ______ are formed.
a. mountains and trees
b. mid-ocean ridges/trenches
c. seashells and sand
b. mid-ocean ridges/trenches
What causes convection currents in the mantle?
a. earthquakes
b. heat and pressure
c. volcanoes
What is an earthquake?
a. magma is released from within the earth
b. earthquakes aren't real
c. two plates slip and waves of energy travel across the earth
c. two plates slip and waves of energy travel across the earth
Most volcanoes form along the Ring of Fire, why?
a. people are more angry there
b. there are lots of mountains causing volcanoes
c. the Pacific plate is subducting beneath many other plates
c. the Pacific plate is subducting beneath many other plates
When magma escapes from the mantle during seafloor spreading, it comes into contact with cold water and forms ________ ________ .
a. mountains and sand
b. trenches and glaciers
c. new crust/rock
c. new crust/rock
What are earth's two types of plates?
a. volcanic and oceanic
b. oceanic and mountainous
c. oceanic and continental
c. oceanic and continental
a. edge
b. jump start
c. epicenter
c. epicenter
Underwater volcanoes along a subduction zone can form _______ .
a. rivers and streams
b. grassy plains
c. islands
c. islands
What happens to the age of the crust as you move farther away from a mid ocean ridge/trench?
a. the crust is younger
b. the crust is the same age everywhere
c. the crust is older
c. the crust is older
________ is when once continental plates slides below the other. ________ is when one plate rises as the other slides beneath it.
a. transform and converge
b. subduction and uplift
c. uplift and transform
b. subduction and uplift
What can happen when two plates collide along a convergent boundary? (Mark ALL that apply.)
a. mountains form
b. landslides and soil liquifaction
c. rivers
d. tsunamis
a. mountains form
b. landslides and soil liquifaction
d. tsunamis
Sometimes, volcanoes occur in the middle of a tectonic plate instead of along a boundary. Why?
a. There are areas in the mantle with magma that is far hotter than usual, and it breaks through the crust.
b. Two plates separate and magma escapes from between them.
a. There are areas in the mantle with magma that is far hotter than usual, and it breaks through the crust.
Seafloor spreading constantly creates new crust. Which process constantly destroys earth's crust?
a. Subduction, when one plate slides below another and heat melts the rock back into the mantle.
b. Tranform, when one plates slides alongside another plate.
a. Subduction, when one plate slides below another and heat melts the rock back into the mantle.