Earth Science: Science Terms Explained

Plain-language definitions of every earth science term your child meets in school, each with kid-friendly explanations, worked examples, and common mistakes to watch for.

Sand dune

A sand dune is a hill or ridge of loose sand that is piled up by the wind, usually found in deserts or along beaches, and can slowly move and change shape over time.

Sediment

Sediment is loose pieces of rock, mineral, or organic material that have been broken down by weathering and moved by wind, water, ice, or gravity, often settling in layers on the land or at the bottom of rivers, lakes, and oceans.

Sedimentary rock

Sedimentary rock is a type of rock that forms when bits of broken rock, minerals, or once-living things settle in layers, get buried, and are pressed and cemented together over time.

Seismic waves

Seismic waves are vibrations that travel through Earth when energy is suddenly released, most often during an earthquake, and they move outward from the source like ripples from a stone dropped in water.

Soil

Soil is the loose, top layer of Earth made from broken-down rock, water, air, and once-living material that supports plant life and many living things.

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