As nouns the difference between supervolcano and supereruption
is that supervolcano
is (volcanology|neologism) a powerful volcano, often having an explosive or cataclysmic eruption while supereruption
(volcanology, neologism) A powerful volcano, often having an explosive or cataclysmic eruption
The massive eruption of a supervolcano.
*2012 , (George Dyson), Turing's Cathedral , Penguin 2013, p. 204:
*:The Los Alamos mesa rested against the eastern slope of the Jemez Mountains, on the rime of the Valles Caldera, formed as a result of two explosive super-eruptions 1.6 and 1.1 million years ago.