Sea Floor Spreading Worksheet featuring a labeled diagram of tectonic activity at a mid-ocean ridge, including molten material, oceanic crust, and continental crust.

1) Mid-ocean ridge
2) Seafloor spreading; new oceanic crust is formed as molten material rises from the mantle and solidifies at the ridge, pushing older crust away on both sides.
3) The old oceanic crust is pushed outward and eventually sinks back into the mantle at subduction zones.
4) Magnetic striping on the ocean floor, age of oceanic rocks increasing with distance from the ridge, and matching geological features on opposite sides of the ridge.
5) Subduction; it occurs because the denser oceanic crust sinks beneath the less dense continental crust due to gravity and plate tectonic forces.
6) Farthest from the mid-ocean ridge, near the continental margins.
7) Sonar
8) Trench
9) Seafloor spreading
10) Subduction
11) Mid-ocean ridge