Which mechanism causes episodic draining of ice-dammed lakes during glacial retreat?

💡 Explanation

When hydrostatic pressure increases behind an ice dam, stress fracturing exceeds the ice's tensile strength, creating conduits for meltwater release, enabling rapid drainage. Therefore, ice fracturing leads to these outburst floods rather than thermo-erosion, cracking or plucking, which involve differential environmental forcing conditions on glacial substrate.

• Which process predominantly facilitates transfer of nutrients required in surface waters by phytoplankton during coastal upwelling events?
• Which mechanism explains sediment layering in glacially-formed proglacial lakes with seasonal meltwater inflow?
• Which mechanism forms bowl-shaped depressions specifically called cirques?
• Which mechanism primarily drives deep ocean thermohaline circulation downwelling in polar regions?
• Which mechanism primarily diminishes near-surface chlorophyll concentrations across equatorial Pacific during El Niño events?
• Which effect promotes plankton blooms when coastal upwelling transports deep water towards the surface?