New Model of The Yellowstone Supervolcano Sheds Light on Its Inner Workings
The basics of what we currently know is that Yellowstone is home to a giant magma chamber underneath the ground, and that it's typically erupted at intervals of about 600,000 years for the last 2 million years or so - the last time Yellowstone fired off was about 630,000 years ago. So now's a great time to learn more about the volcano, and we are making progress on that front.
New research from the University of Oregon, just published in Geophysical Research Letters, shows a more comprehensive look at the magma chamber, all thanks to a computer model the team was able to put together. This model, while mostly mathematical, reveals that this giant chamber contains a "transition zone" in the form of a mid-crustal sill that plays a big role in how deep magma rises to the surface.
What is the source of Yellowstone's heat? New research suggests that it comes from deep within the Earth. Check out #Yellowstone #CalderaChronicles for the full story: https://t.co/SmY9OE0oG2 pic.twitter.com/qJadJ3QDlY— USGS Volcanoes (@USGSVolcanoes) April 16, 2018
The model confirms recent discoveries that the volcano is even larger than we thought, with the initial magma chamber located 2.5 and 8.7 miles (4 to 14 kilometers) beneath the surface, and a second magma chamber at about 12 to 27 miles (20 to 45 km) deep. What separates these two areas is the mid-crustal sill shown off by the model, about 6.2 to 9.3 miles (10 to 15 kilometers) thick.
And this unmelted sill/shelf is important, as this is where cold rocks meet with the hot magma which pools up and collects over the crustal shelf. From here, it has a much easier journey to the surface in the event of an eruption, and on top of this, this magma plume is about 315 degrees Fahrenheit (175 degrees Celsius) hotter than the mantle surrounding it.
The model was created using a technique called "forward modeling", by using established data to run scenarios and predict new outcomes. And most importantly, it can arrive independently at newer findings about the volcano made back in 2014 and 2015 (which was when we first discovered that second magma chamber) which is a good sign for its accuracy.
Now, none of this can help us directly predict when the next eruption will be, but it's an important step toward that.