Continental Drift and Seafloor Spreading

• Convection is a process where materials move due to heat and density differences, leading to the circulation of heated and cooled particles.
• In Earth's mantle, hot and less dense rocks rise, while cooler and denser parts sink.
• Plate movements are driven by three main theories: mantle convection, ridge push, and slab pull.
• Plates move at rates of 1-10 centimeters per year, with three main types: divergent, convergent, and transform.
• Divergent boundaries occur when plates move apart, resulting in rift valleys and volcanic activity.
• Convergent boundaries occur when plates collide, leading to mountain building, earthquakes, and volcanic activity.
• Transform boundaries occur when plates slide past each other, causing friction and earthquakes.
• Tectonic plate movement can cause various geological changes, including volcanic activity, earthquakes, mountain building, and continental drift.
• Once a giant landmass called Pangaea, Earth's continents separated and moved into their current configurations due to plate movements.
• Tectonic plate movements generate heat and energy, leading to the formation of different types of mountains through uplift, folding, and volcanic activity.
• Earthquakes occur when the energy released by plate movements creates faults in the Earth's crust.
• Hot spots, or mantle plumes, can create volcanoes through the melting of mantle rock into magma, which then rises and forms a volcano on Earth's surface.
• Stress created by plate movements is a significant factor in the occurrence of earthquakes.

Learn about the early evidence for continental drift and the later development of the theory of seafloor spreading, which helped to explain the movement of continents. Discover the contributions of Wegener and Hess to our understanding of Earth's geology.