Surface Processes: Soils

Climate and Temperature

Learn how Earth's climate effects soil types all over the planet.

Critical Zone

The Critical Zone (CZ) is defined as the zone at Earth’s land surface extending from the top of the vegetation canopy through soil to subsurface depths at which fresh groundwater freely circulates. This is the zone where most terrestrial life — including humanity — resides. Learn more about this important space in this activity from the Critical Zone Observatories.

Density of Minerals

Density is an intrinsic physical property of minerals that relates to the composition of the mineral and to the pattern in which the mineral’s atoms are arranged. “Intrinsic” means that the property is the same for the mineral, no matter what the size or shape of the sample. In this activity, students will measure and compare the densities of minerals.

Dig Into Soil

Learn how soil scientists observe and record data and how that information is useful to farmers, builders, and others in order to use the land appropriately.

Energy Efficiency

Even in an area with an extreme climate, the ground maintains a relatively constant temperature. Because of this, a house that is built partly or entirely underground can be more energy-efficient than a home above ground. During the winter, the ground is warmer than the air. During the summer, it is cooler. Any large mass of earth tends to maintain a constant temperature. You can see for yourself how this works by testing how long it takes for a thermometer buried in sand or soil to reach the temperature of surrounding air.

Exploring Porosity

Earth scientists play a vital role in harvesting the energy resources on which we all rely. When preparing to drill for oil, for example, geoscientists must assess many aspects of a rock stratum (layer). For example, they must figure out the volume of the rock’s pores, or empty spaces, as compared with the rock’s total volume. This is called the rock’s porosity. To help you understand porosity, think about different sizes of gravel. Which size gravel will have the greatest porosity? Why? In this activity, you will work in groups to explore the answers to these questions.

Finding Slope

Explore how the slope of land will effect water flow and life above ground in this activity from the Soil Science Society of America.


Learn the dangers of flooding in this activity, where students explore soil porosity and permeability.

How Can You Test Your Soil?

As a citizen scientist, you can use a soil test kit to find out how much of each type of chemical is in your soil.

How Much Soil Is There?

All living things depend on soil to live. But how much soil is there?


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