Which mechanism contributes to the oxygen stratification observed in deep fjords containing density gradients?

💡 Explanation

When density gradients occur in a fjord, haloclines inhibit mixing because denser saline water underlies less dense freshwater, restricting oxygen diffusion from surface waters to depth. As consequence, option A is correct reflecting this stable layering effect, instead of options invoking mixing or photosynthesis.

• Which adjustment occurs when increased glacial meltwater alters stream salinity, affecting thermohaline circulation?
• Which mechanism amplifies temperature gradients at mid-latitudes when polar Hadley cell boundaries shift equatorward?
• Which mechanism causes fjord sill formation at the mouth of a glacial valley?
• Which outcome commonly occurs from increased silt weathering in loess deposits?
• Which risk increases when thermohaline circulation weakens substantially due to polar ice melt?
• Which condition accelerates karst landscape development by leaching?