An Insolation Activated Dust Layer on Mars

Abstract

The illuminated dusty surface of Mars acts like a gas pump. It is driven by thermal creep at low pressure within the soil. In the top soil layer this gas flow has to be sustained by a pressure gradient. This is equivalent to a lifting force on the dust grains. The top layer is therefore under tension which reduces the threshold wind speed for saltation. We carried out laboratory experiments to quantify the thickness of this activated layer. We use basalt with an average particle size of 67 $\mu$m. We find a depth of the active layer of 100 to 200 $\mu \mathrm{m}$. Scaled to Mars the activation will reduce threshold wind speeds for saltation by about 10%.

6 pages, 9 figures, accepted by Icarus

References in corpus (3)

• From Planetesimals to Dust: Low Gravity Experiments on Recycling Solids at the Inner Edge of Protoplanetary Disks
• Crossing barriers in planetesimal formation: The growth of mm-dust aggregates with large constituent grains
• Dust Ejection from Planetary Bodies by Temperature Gradients: Laboratory Experiments

Cited by in corpus (8)

• Formation of recurring slope lineae on Mars by rarefied gas-triggered granular flows
• Understanding planet formation using microgravity experiments
• Is There a Temperature Limit in Planet Formation at 1000 K?
• Thermal creep assisted dust lifting on Mars: Wind tunnel experiments for the entrainment threshold velocity
• Lifting Grains by the Transient Low Pressure in a Martian Dust Devil
• Analog Experiments on Tensile Strength of Dusty and Cometary Matter
• Selective Aggregation Experiments on Planetesimal Formation and Mercury-Like Planets
• Thermal Creep on Mars: Visualizing a Soil Layer under Tension