The document summarizes key aspects of Earth's internal structure, surface features, tectonic plates, earthquakes, volcanoes, and landforms. The Earth has a solid crust on top of a thick mantle and liquid outer and solid inner cores. Over 70% of the surface is ocean, covering underwater volcanoes, mountains and trenches. The remaining 30% includes various landforms like forests and deserts. Tectonic plates float on the mantle and interact, causing earthquakes and forming volcanoes and mountains. Earthquakes generate seismic waves and tsunamis. Volcanoes form at plate boundaries and erupt molten magma from the crust. Important landforms include mountains, valleys, plains and coastal features.

1. Terrain