Final answer:
The term for extremely violent volcanic eruptions that bring magmatic material from the mantle to the Earth's surface quickly is 'supervolcanic eruptions' or 'supereruptions.' These eruptions can form large calderas and affect climate, and one historic example is the Gray's Landing supereruption above the Yellowstone hotspot.
Step-by-step explanation:
Extremely Violent Volcanic Eruptions
The term used to describe extremely violent volcanic eruptions that rapidly bring magmatic material from the upper mantle to the Earth's surface is supervolcanic eruptions or supereruptions. Such eruptions can create large calderas and have the potential to affect global climate due to the enormous volume of material expelled. Supervolcanic events, like the one from the Yellowstone hotspot, are examples of hotspots causing massive eruptions in the past. The heat supplied by hotspots can accelerate the rise of magma, leading to powerful eruptive events. In the case of Yellowstone, the Gray's Landing volcanics represent a significant past supereruption.
Volcanism and the hazards associated with it are crucial in understanding the geodynamics of Earth. Hotspots are one of the main sources of such volcanic activity, with the Hawaiian hotspot being another well-known location where ongoing volcanic activity is observed. In geographically diverse areas, the nature of volcanic material and eruptions can vary significantly, as seen in the differences between oceanic and continental hotspot volcanism.