#3 is a convergent boundary where one of the plates moves under the other plate due to gravity and differences in density.
#4 is a divergent plate boundary where a new ocean floor is created as the plates spread apart. It is the most extensive chain of mountains on earth, but more than 90% of this mountain range lies in the deep ocean (the "spreading center").
(2 points)
1 answer
Based on your description, for the labels:
#3: Subduction Zone (convergent boundary where one plate moves under another).
#4: Mid-Ocean Ridge (divergent plate boundary where new ocean floor is created).
If you have an image or diagram specifically, you would label #3 as "Subduction Zone" and #4 as "Mid-Ocean Ridge."
