Geography-chapter1-plate tectonics

What are tectonic plates?

Huge pieces of the Earth's crust that move on the semi-molten mantle.

What causes plates to move?

Convection currents in the mantle created by heat from the core.

Who proposed the idea of Continental Drift?

Alfred Wegener.

What evidence supports Continental Drift?

Matching fossils, rock types, and coastlines across continents.

What are the three main types of plate boundary?

Constructive, Destructive, and Passive (Transform).

What happens at a constructive boundary?

Plates separate, magma rises, new crust forms (e.g. Mid-Atlantic Ridge).

What happens at a destructive boundary?

Plates collide, subduction occurs, and fold mountains or volcanoes form.

What happens at a passive boundary?

Plates slide past each other causing earthquakes (e.g. San Andreas Fault).

Name the three main layers of the Earth.

Crust, Mantle, Core.

What is the difference between continental and oceanic crust?

Continental is thicker and lighter; oceanic is thinner and denser.