Sublimation-driven morphogenesis of Zen stones on ice surfaces

Area of Science:

• Geophysics and natural phenomena.
• Physics of phase transitions and material science.

Background:

• Zen stones are natural formations where stones balance on ice pedestals.
• Their formation is often misattributed to melting, but involves complex physical processes.

Purpose of the Study:

• To elucidate the physical mechanism behind Zen stone formation.
• To explain the role of sublimation and a stone's shading effect on ice pedestal morphogenesis.

Main Methods:

• Laboratory experiments using a lyophilizer with model stones (metal disks).
• Numerical simulations incorporating sky visibility and sublimation rates.
• Analysis of differential ablation due to solar radiation and shading.

Main Results:

• Sublimation, not melting, is the primary mechanism driving pedestal formation.
• A stone acts as a shade, inhibiting sublimation and creating an ice pedestal.
• The stone's shape influences pedestal formation, and its thermal radiation creates a surrounding depression.

Conclusions:

• Zen stone formation is a sublimation-driven process governed by differential ablation.
• The shading effect of the stone is crucial for pedestal morphogenesis.
• Further research can explore variations in stone shape and environmental conditions.