Onset of Glacier Tables

Area of Science:

• Geophysics
• Glaciology
• Thermodynamics

Background:

• Glacier tables are naturally occurring geological formations.
• These structures consist of a rock or debris resting on an ice pedestal.
• Their formation mechanism on glaciers is not fully understood at smaller scales.

Purpose of the Study:

• To investigate the formation of glacier tables at a smaller scale.
• To understand the physical processes governing the initial stages of glacier table development.
• To identify key parameters controlling the transition between different formation regimes.

Main Methods:

• Controlled laboratory experiments simulating glacier table formation.
• Utilizing various cap sizes and thermal conductivities.
• Development and application of a one-dimensional conduction model.

Main Results:

• Observed two distinct formation outcomes: stable tables on ice feet or sinking into the ice.
• Modeled differential ice melting as a competition between geometrical amplification and heat flux reduction.
• Identified a dimensionless number critical for controlling formation onset.

Conclusions:

• The formation of glacier tables is governed by the interplay of geometry and thermal properties.
• A dimensionless number effectively predicts the transition between stable table formation and sinking.
• The study provides a foundational model for understanding these unique glacial features.