Plate tectonics and continental drift

Front

What is plate tectonics?

Back

The theory that explains the structure and movement of Earth's lithosphere, which is divided into tectonic plates that float on the semi-fluid asthenosphere.

Front

Define continental drift.

Back

The hypothesis that continents have moved over geological time and were once joined together in a single landmass called Pangaea.

Front

What is subduction?

Back

The process where one tectonic plate moves under another plate and sinks into the mantle, often leading to volcanic activity.

Front

What evidence supports the theory of continental drift?

Back

Fossil evidence, matching geological formations, and glacial patterns found on different continents.

Front

What is seafloor spreading?

Back

The process by which new oceanic crust is formed at mid-ocean ridges and older crust is pushed away from the ridge.

Front

How do oceanic and continental crust differ in density?

Back

Oceanic crust is denser (3.2 g/cm³) than continental crust (2.8 g/cm³), which affects their interactions at plate boundaries.

Front

What happens when oceanic and continental plates collide?

Back

The denser oceanic plate sinks beneath the continental plate, leading to subduction.

Front

What role do oceanic trenches play in plate tectonics?

Back

Oceanic trenches are formed at subduction zones and indicate where oceanic crust is being destroyed.

Front

What is the significance of Alfred Wegener's theory?

Back

Wegener proposed the idea of continental drift, which laid the groundwork for modern plate tectonic theory, despite initial skepticism.

Front

How do volcanic chains provide evidence for plate tectonics?

Back

Volcanic chains often align with tectonic plate boundaries, indicating the movement and interaction of plates.