1. vertical shafts or tunnels in glaciers formed by meltwater flowing down through cracks in the ice
Usage: glaciology; geology

Examples

• The researchers studied the moulins to understand glacial meltwater drainage.
• Deep moulins carved through the ice sheet carried surface water to the bedrock below.
• Climate change has increased the formation of moulins in Greenland’s glaciers.
• The expedition team carefully avoided the dangerous moulins while crossing the glacier.
• Scientists dropped sensors into the moulins to measure water flow rates.
• The blue-green walls of the moulins revealed layers of compressed ice.