Porosity: The amount of open space within a rock or sediment. Porous materials, like sandstone or gravel, have high porosity and can hold more water.
Permeability: The ability of a material to transmit fluids. Materials with high permeability allow water to flow through them easily, while those with low permeability hinder the flow of water.
Water Table: The upper surface of the zone of saturation, where the water fills all the spaces in the rock and sediment.
Develop and use models of Earth’s interior composition to illustrate the resulting magnetic field (e.g., magnetic poles) and to explain its measureable effects (e.g., protection from cosmic radiation).