Which mechanism significantly reduces surface salinity in areas of intense oceanic upwelling?

💡 Explanation

When upwelling occurs, vertical advection brings deep water to the surface because density differences drive the circulation, reducing surface salinity because the deeper ocean layers often contain fresher water from glacial melt or river outflow. Therefore, deep water entrainment results, rather than evaporation, ice, or productivity effects which would increase surface layer concentration.

• Which risk increases in buildings founded on loosely packed, saturated soil during an earthquake?
• Which risk increases when volcanic mudflows meet permafrost?
• Which geological feature results primarily from sediment accretion within an oceanic trench in a subduction zone?
• Which outcome occurs when consistent winds shape ventifacts?
• Which outcome results when vegetation cover is removed, triggering increased frequency of deflation events on loess deposits?
• Which type of seismic hazard risk increases following triggered creeping fault behavior?