Which mechanism causes mantle plume volcanism far from subduction zones or plate boundaries?

💡 Explanation

When the mantle is locally heated, a mantle plume forms due to thermal expansion, causing buoyant upwelling because hot material is less dense, leading to volcanism far from plate boundaries. Therefore, buoyant upwelling results, rather than extrusion, sliding, or rollback which are related to plate boundary forces.

• Which process primarily drives thermohaline circulation in the ocean during winter?
• Which mechanism causes increased coastal subsidence during an earthquake along a subduction zone lacking sediment?
• Which phenomenon primarily causes the deflection of large subtropical ocean currents?
• Which outcome occurs when the hydraulic gradient decreases sharply along a river flowing into a lake?
• Which oceanographic effect emerges with increased glacial melting?
• Which pedogenic effect follows enhanced chemical weathering by increased acidity?