Understanding Booming Sand Dunes

What is unique about the Dumont Dunes in California?

• They are made entirely of quartz sand.

• They are the largest dunes in the world.

• They are one of the few places where dunes sing.

• They are the oldest dunes on Earth.

How does sand behave when it is poured out of your hand?

• It acts like a gas.

• It acts like a solid.

• It acts like a plasma.

• It acts like a fluid.

What happens when the downstream face of a sand pile reaches the angle of repose?

• The sand pile spontaneously avalanches.

• The sand pile starts to grow.

• The sand pile becomes stable.

• The sand pile collapses.

What is required for a sand dune to produce a musical tone?

• The sand must be wet.

• The dune must be small.

• The sand must be dry and the dune must be large.

• The dune must be covered in vegetation.

What is the role of the upper layer of sand in producing the booming sound?

• It dampens the sound.

• It amplifies the sound.

• It reflects the sound.

• It absorbs the sound.

What is the impact of desertification on agricultural land?

• It increases the fertility of the land.

• It leads to the loss of agricultural land.

• It has no impact on agricultural land.

• It reduces the size of sand dunes.

What percentage of Earth's surface is projected to be degraded by 2050?

• 60%

• 50%

• 90%

• 75%

What did Nathalie and Karol discover about miniature dunes in their experiments?

• They always move at the same speed.

• They communicate and negotiate for space.

• They never change their position.

• They move independently without interaction.

What is the main goal of Nathalie's ongoing research?

• To create artificial dunes.

• To increase the size of dunes.

• To stop all dune movement.

• To understand and mitigate dune migration.

How do the dunes in the lab differ from those in the real world?

• They do not produce any sound.

• They are larger than real-world dunes.

• They move faster due to the use of fluid.

• They are made of different materials.