From the BBC:
http://www.bbc.com/future/story/20170817-nasas-ambitious-plan-to-save-earth-from-a-supervolcanoI recognize the BBC, which makes it seem like a more credible source.
One possibility (for stopping an eruption) is to simply increase the amount of water in the supervolcano. But from a practical perspective, it would likely be impossible to convince politicians to sanction such an initiative.
“Building a big aqueduct uphill into a mountainous region would be both costly and difficult, and people don’t want their water spent that way,” Wilcox says. “People are desperate for water all over the world and so a major infrastructure project, where the only way the water is used is to cool down a supervolcano, would be very controversial.”
This is still sci-fi level stuff, like a meteor hitting the Earth, however...
“I was a member of the Nasa Advisory Council on Planetary Defense which studied ways for Nasa to defend the planet from asteroids and comets,” explains Brian Wilcox of Nasa’s Jet Propulsion Laboratory (JPL) at the California Institute of Technology. “I came to the conclusion during that study that the supervolcano threat is substantially greater than the asteroid or comet threat.”