However , by observing the fracture zones , one can determine both the direction and rate of past plate motion .
As many areas of the ocean floor , particularly the Atlantic Ocean , are currently inactive , it can be difficult to determine past plate motion .
By observing the fracture zones , one can determine both the direction and rate of past plate motion .
As many areas of the ocean floor , particularly the Atlantic Ocean , are currently inactive , it can be difficult to determine past plate motion .