Which mechanism causes increased coastal upwelling during La Niña conditions?

💡 Explanation

During La Niña, stronger easterly trade winds increase the pressure gradient because of the intensified Walker circulation, leading to greater Ekman transport and upwelling along the western coast of South America. Therefore enhanced trade wind pressure results, promoting upwelling, rather than changes in thermohaline fronts, meltwater impact or gyre circulation, which have different primary drivers.

• Which risk increases when an oceanic plate subducts beneath a continental plate with high sediment cover?
• Which mechanism amplifies stream meandering on coastlines undergoing isostatic rebound due to melting glaciers?
• Near subduction plate boundaries, which risk increases when fault locking intensifies?
• Which mechanism causes loess deposition next to glacial outwash?
• Which outcome dominates when a locked subduction zone ruptures?
• Which outcome occurs when a locked fault suddenly ruptures?