Development of a Theory

Front

What are ocean trenches?

Back

Deep underwater troughs on the seafloor.

Front

What is seafloor spreading?

Back

The process by which new oceanic crust is continuously formed and destroyed.

Front

What are mid-ocean ridges?

Back

Vast mountain ranges deep below the ocean's surface.

Front

What is the significance of seafloor spreading in understanding oceanic crust age?

Back

Seafloor spreading helps explain the age of oceanic crust and ocean-floor features.

Front

What happens to the density of seafloor as it moves away from an ocean ridge?

Back

The seafloor cools and becomes more dense than the material beneath it.

Front

What is subduction?

Back

The process where one tectonic plate moves under another and sinks into the mantle.

Front

What is continental drift?

Back

The theory that continents have moved over geological time and were once joined together.

Front

What is the role of tectonic plates in ocean formation?

Back

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

Front

What is the relationship between ocean trenches and subduction zones?

Back

Ocean trenches are formed at subduction zones where one plate is forced under another.

Front

How do oceanic and continental crust differ?

Back

Oceanic crust is denser and thinner than continental crust.