These are the longest chain of mountains in the world
What is Mid-Ocean Ridge
100
This processes adds more crust to the ocean floor as well as pushes older strips of rock outward from either side of the ridge
What is Sea-Floor Spreading
100
Ocean floor plunges into deep underwater canyons
What is Deep-Ocean Trenches
100
Newly formed rock is made__________ way from the mid-ocean ridge
What is closer
100
near the of the mid-ocean ridge the crust is_______ dense
What is less
200
this device measures ocean depth by bouncing sound waves off underwater objects and timing the echoes
What is Sonar
200
Scientist use 3 types of ________ to prove that there is sea-floor spreading
What is evidence
200
Process by which ocean floor sinks beneath a trench and back into the mantle
What is Subduction
200
The pattern of stripes on either side of the ridge are not the same. (true or false)
What is False
200
Farther away from the mid-ocean ridge the crust is ______(older/younger)
What is older
300
Mid- Ocean Ridge extends to all oceans like the seam of this type ball
What is a baseball
300
Rocks that form from when molten material hardens quickly after erupting under water.
What is Pillow Lava
300
The Pacific Ocean has more trenches than mid-ocean ridges. Therefore, more subduction takes place than new crust forming, so the pacific ocean is getting____?
What is Smaller
300
A process that takes up to tens of millions of years to have part of the ocean floor sink back into the mantle is done where
Deep-Ocean Trenches
300
Under the lithosphere these currents push new crust to the sides, and new magma rises to form even new ocean crust
What is Convection
400
Mid-Ocean Ridge is split by this type of land form
What is a steep sided valley
400
evidence used to prove sea-floor spreading was found by taking material from the ocean floor.
What is Drilling Samples
400
The Atlantic Ocean has very few trenches and ocean floor has nowhere to subduct. As the ocean floor expands, it carries attached continents with it, so the Atlantic Ocean is getting_____
What is Wider
400
Processes that can change the size and shape of the oceans
What are subduction and sea-floor spreading
400
At the Pacific Ocean's deep-ocean trenches, oceanic crust is _________
What is subducted
500
At the Mid-Ocean Ridge molten material rises from the mantle. What happens to the material after this happens?
The material spreads out on both sides of the ridge and pushes older rock aside to both sides of the ridge
500
evidence that shows Earth's magnetic poles have reversed themselves many times
What is Magnetic Stripes
500
The rate at which new crust is being created at the mid-ocean ridge and how fast old crust is being swallowed up at deep-ocean trenches determines this.
What is the size of Earth's oceans
500
A deep ocean trench is an underwater mountain (true or false)
What is false
500
these processes take up to 200 million years to make the ocean floor renewed.