The Porosity Gizmo demonstrates that is the primary driver of permeability, while porosity depends more on how well-sorted the grains are rather than their absolute size. For efficient water storage and retrieval (aquifers), materials with high permeability and high porosity, such as gravel or coarse sand, are ideal.
The experiment utilizes the Porosity Gizmo to test three sediment types: Fragments > 2.0 mm. Sand: Grains between 0.0625 mm and 2.0 mm. Silt: Grains between 0.0039 mm and 0.0625 mm. Activity A: Testing Permeability Step 1: Reset containers and turn on the macroscopic view. student-exploration-porosity-gizmo-answers
Calculate the porosity percentage using the formula: The Porosity Gizmo demonstrates that is the primary
Record the presence of surface water, which indicates the sediment is either saturated or has low permeability. Activity B: Calculating Porosity Sand: Grains between 0
Water passes through gravel most easily because the large pore spaces allow for faster flow. Silt has the lowest permeability because its small pores create more friction and "tight" paths for water.
Surprisingly, uniform spheres of different sizes (like the marble vs. small beads example) often have the same total porosity. The volume of empty space remains constant if the grains are well-sorted, even if the individual holes are smaller.