The hypothetical drill won’t actually plunge into the magma itself; that would risk causing a massive depressurization event that might even set the monster off. It’ll sit a short distance above the primary chamber – at around a depth of 10 kilometers (6.2 miles) – where hydrothermal fluids heated by the magma course their way to the surface.
These fluids actually rob the magma of up to 70 percent of the magma’s thermal signature already. NASA will simply add more water, under extremely high pressures, in order to ramp up this cooling process.
In order not to accidentally fracture the surrounding rock and shatter the roof of the magma chamber, NASA suggests that it might be a better idea to drill underneath the magma chamber. This would be somewhat problematic, as any instance of fresh magma emerging from below would destroy the borehole and re-heat the shallow magma chamber once again, making it potentially eruptible and ruining NASA's epic scheme to save the Land of the Free.
A second option – one in which the magma chamber (or chambers) would be directly drilled into, and pressure from within would be released – was considered, but rejected. Either this would cause the overlying rock to crack and cause a major depressurization event, or the borehole would melt and quickly seal up, preventing any pressure leakage from taking place.
In any case, if this cooling plan was ever approved of, it would cost around $3.5 billion. Pricey, but if the result is saving the planet, then we’d argue that’s a fair price to pay. It’s also 0.6 percent of the annual budget for the US Armed Forces, so there’s that.
NASA has pointed out, however, that their plan essentially pays for itself over time. All that excess heat has to go somewhere, so why not siphon it off and use it to power some of America’s electrical grid?
Either way, this story has a tinge of melancholy to it. Cooling the chamber so that it becomes mostly uneruptible would take thousands of years, which means that those that started the project would never know if their mission succeeded.
As aforementioned, this is likely to be a thought experiment at this stage, and we wouldn't expect drilling to begin anytime soon. What this white paper is designed to do is provoke debate about the threats posed by supervolcanoes, and to begin to think about what, if anything, we can do to reduce their impacts apart from improving out prediction models.
This is fair enough. Although unlikely to happen for a considerable amount of time, if ever, a supervolcanic blast akin to its very first 2.1 million years ago would generate 2,500 times the amount of volcanic material as the 1980 destruction of Mount St Helens. Apart from the potentially devastating regional and global effects such an eruption would bring about, tens of thousands of people in Yellowstone National Park would die almost instantly via pyroclastic flows and the collapse of the caldera roof.
This could happen again, but just imagine for a second that we could engineer a way to prevent it. Now wouldn't that be lovely?