Seafloor Spreading & Continental Drift

Front

What is seafloor spreading?

Back

Seafloor spreading is the process by which new oceanic crust is formed at mid-ocean ridges as molten material rises from the mantle and solidifies.

Front

Where does molten material rise during seafloor spreading?

Back

Along the mid-ocean ridge.

Front

What is the hypothesis of continental drift proposed by Alfred Wegener?

Back

Wegener's hypothesis suggested that continents were once joined together and have since drifted apart, but it lacked sufficient evidence at the time.

Front

What is the age of the oldest ocean crust?

Back

The oldest ocean crust is about 180-200 million years old.

Front

What are mid-ocean ridges?

Back

Mid-ocean ridges are vast underwater mountain chains that are the largest geological features on Earth.

Front

What is subduction?

Back

Subduction is the process where one tectonic plate moves under another and is forced into the mantle.

Front

What evidence supports the theory of continental drift?

Back

Evidence includes the fit of continental coastlines, fossil distribution, and geological similarities across continents.

Front

What role do tectonic plates play in seafloor spreading?

Back

Tectonic plates move apart at mid-ocean ridges, allowing magma to rise and create new crust.

Front

What is the significance of the mid-ocean ridge?

Back

The mid-ocean ridge is significant as it is the site of seafloor spreading and the formation of new oceanic crust.

Front

How does seafloor spreading affect oceanic crust?

Back

Seafloor spreading continually adds new crust to the ocean floor, pushing older crust away from the ridge.