hypervolcano

Examples

• 2007 August 2, History Doomed To Repeat, at www.unexplained-mysteries.com Yes, there is always the uncertainty of some natural disaster overwhelming the US and precipitating a collapse. The eruption of the hypervolcano under Yellowstone could be such an event, or the collapse of the volcanic cone (forget it's [sic] name) in the Canary Islands sending a tsunami to devastate the east coast. However these are unpredictable and I don't consider such events as repetitions of some unalterable historical cycle of the rising and falling of civilisations.
• 2015 November 09, Volcanoes on Pluto look a lot like those on Earth and Mars, at arstechnica.com It's all about your perspective. 80 years ago, EE Smith was writing about the inhabitants of Titan being awed by a creature whose blood was based on molten water. If there were anything living on Pluto (or maybe in the proposed ammonia-slush mantle inside) they would be completely freaked out at the idea that on the inner planets all of their most common liquids and solids were gaseous, yet life persisted. They would probably have to coin some word like "hypervolcano" to name that thing with molten silicates erupting.
• 2016 April 18, What would it feel like on the surface of a planet while it collides with another planet?, at worldbuilding.stackexchange.com There is a documentary on nova with scientists discussing the effect of a neutron star invading the solar system, it's totally false because the iron of the earth would compress against the crust like a huge hypervolcano, and pop out of the breach in the crust and fly into space, long before stones would start to fly around.