Surface & interior

A lava flow

The Earth's surface is home to spectacular and frightening sights and experiences that hint at what is happening deep within the planet. Volcanoes and earthquakes are powerful evidence of the tectonic plates that grind against one another and the magma that rises through an inner layer known as the mantle.

Plate tectonics, a theory central to modern geology, explains so much of what we see happening around us. Through this theory, we now understand how mountains form, why there are different types of volcano, and how the land surface is constantly renewed.

The pages in this section contain video clips from popular television series such as Earth: Power of the Planet, presented by Iain Stewart, Horizon, Bang Goes the Theory, and How the Earth Made Us.

Image: Lava flows from Kilauea volcano into the sea in Hawaii (credit: Doug Perrine/

Surface & interior

  • Composite volcanoesComposite volcanoes

    Composite volcano eruptions are often the most deadly.

  • ErosionErosion

    Rain, wind and ice constantly wear down the Earth's surface.

  • HotspotsHotspots

    The Hawaiian islands owe their existence to a hotspot.

  • Impact cratersImpact craters

    Asteroids and comets will continue to strike the Earth.

  • Inside the EarthInside the Earth

    Earthquakes help geologists understand the Earth's inner structure.

  • LavaLava

    Aa is a Hawaiian name for a type of lava.

  • MagmaMagma

    Large bodies of molten rock exist below the Earth's surface.

  • Mid-ocean ridgesMid-ocean ridges

    New sections of the Earth's tectonic plates form deep in the oceans.

  • MineralsMinerals

    There are thousands of minerals on Earth.

  • Mountain formationMountain formation

    Most mountains are formed at tectonic plate boundaries.

  • Plate boundariesPlate boundaries

    Earthquakes and volcanoes are common at plate boundaries.

  • Plate tectonicsPlate tectonics

    A theory explains why many of the continents fit together.

  • RocksRocks

    Rocks are a valuable record of the Earth's history.

  • Shield volcanoesShield volcanoes

    Shield volcanoes are huge, but less explosive.

  • SupercontinentsSupercontinents

    In the past the continents have been joined together.

  • The rock cycleThe rock cycle

    Rocks change their form over very long time periods.