Subglacial floods under pressure create aerodynamic drumlin shapes through glacial till

Subglacial floods under pressure create aerodynamic drumlin shapes through glacial till. Drumlins only form under ice where water is under pressure High-pressure subglacial water erodes upward into glacier bottom and downward into glacial till Water sculpts till into aerodynamic shapes minimizing frictional drag

How do drumlins form? Under ice, pressurized subglacial water erodes UPWARD into the glacier AND downward into glacial till, sculpting aerodynamic shapes that minimize drag. Researchers note ceiling patterns in subglacial tunnels mirror floor patterns—and the principle is similar to boat hull design. Water under pressure is remarkably efficient at shaping land.

Key Facts

• Drumlins only form under ice where water is under pressure
• High-pressure subglacial water erodes upward into glacier bottom and downward into glacial till
• Water sculpts till into aerodynamic shapes minimizing frictional drag
• Ceiling patterns in subglacial tunnels mirror floor patterns
• Process similar to boat hull design principles applied to water flow

Source: The Finger Lakes All Radiate From The Same Spot by The Randall Carlson