Understanding Sand Dunes

What is the term used to describe the wind speed necessary to move sand particles?

• Critical wind speed

• Sand transport velocity

• Fluid threshold velocity

• Aeolian velocity

Which process involves sand particles being lifted into the air and then falling back to the surface?

• Deposition

• Suspension

• Surface creep

• Saltation

What shape do dunes typically have?

• Flat with no slope

• Gradual upward slope and steep downward slope

• Uniform slope on both sides

• Steep upward slope and gradual downward slope

Which of the following is NOT a condition necessary for dune formation?

• Large tidal ranges

• High humidity levels

• Abundant supply of sediment

• Ample wind energy

Why are beaches with large tidal ranges more likely to have dunes?

• They are closer to cliffs

• They have stronger winds

• They allow more time for sand to dry

• They have more vegetation