Urban Planner — Lesson 2
Lesson 2 of Geography focuses on plate tectonics, the unifying theory of Earth science that explains the distribution of earthquakes, volcanoes, mountain ranges, and ocean basins. Earth's lithosphere is divided into approximately 15 major tectonic plates and several smaller ones that move at rates of 1–10 centimeters per year. Key variants of plate boundaries include divergent boundaries (mid-ocean ridges where plates move apart), convergent boundaries (where oceanic crust subducts beneath continental crust), and transform boundaries (where plates slide horizontally past each other).