Plate Tectonics and Earthquakes: Earth Science Study Guide Subject: Science | Grade: Grade 6-9 Our Earth might feel solid beneath our feet, but the crust is actually broken into massive puzzle pieces called tectonic plates. These plates float on a semi-liquid layer of rock underneath and are constantly moving. Here is an overview of how these moving plates shape our planet's surface and cause earthquakes: Layers of the Earth To understand plate tectonics, we must look at the Earth's layers: • Crust: The outer, solid rock layer we live on. • Mantle: The thickest layer made of hot, semi-molten rock. • Outer Core: Liquid iron and nickel. • Inner Core: A solid ball of iron and nickel under extreme pressure. Types of Plate Boundaries Tectonic plates meet at boundaries. Depending on how they move, they create different geographical features: • Divergent Boundaries: Plates pull apart (e.g., Mid-Atlantic Ridge). Magma rises to create new crust. • Convergent Boundaries: Plates collide (e.g., Himalayas). One plate may slide under the other (subduction), creating volcanoes and mountains.