Continental drift

• Continental drift is the movement of landmasses across the Earth's surface over time.
• Mid-ocean ridges are underwater mountain ranges that run through the Atlantic Ocean.
• Subduction zones occur where two oceanic plates collide, with one plate being forced beneath the other into the mantle.
• Convection currents drive seafloor spreading by carrying hotter material upwards towards the ocean floor and colder material downwards back into the mantle.
• Pangaea was a supercontinent formed about 200 million years ago.
• Oceanic crust is thinner than continental crust.
• Convergent boundaries can be destructive (subduction) or constructive (continent collision).
• Constructive plate boundaries form volcanoes and earthquakes, while destructive plate boundaries cause earthquakes and tsunamis.
• Divergent boundaries form when two plates move apart, causing seafloor spreading and the formation of mid-ocean ridges.
• Convergent boundaries form when two plates meet head-on, resulting in subduction or collision.
• The Earth's core consists of an inner solid core (made mostly of iron) surrounded by a liquid outer core (also made mostly of iron).
• Seismic waves travel at different speeds depending on their type and the materials they pass through.