Hooray, there’s a new study on the Yellowstone supervolcano out! No, it’s not about to erupt, nor is it now any more or less dangerous than we thought. Just thought we’d clear that up right at the beginning.
So what’s this one all about? Well, it’s a supercomputer simulation of the engine beneath Yellowstone, which aims to clarify a few details about its current state and its evolution over the last few million years. As it so happens, their conclusions provide fresh insight into how the infamous caldera's underlying magmatic system came to be.
Thanks to the incredible work of interdisciplinary scientists, we've come to know a fair bit about Yellowstone in the last few decades. For example, we know, through the use of ground-penetrating seismic waves, that its magma chamber has a shallower, more viscous, rhyolitic upper section, and a far more voluminous basaltic lower section. (Both, incidentally, are mostly solid, which is one of the reasons we aren't expecting any sort of eruption anytime soon.)
That’s where our supercomputer simulation comes in. The authors used it to focus on “how the observed structure of Yellowstone's current magmatic system – that of a 2-layer complex – came to be,” Dr Michael Poland, the Scientist-in-Chief at Yellowstone Volcano Observatory – who wasn’t involved in the study – told IFLScience.
Geophysical data indicates that the upper chamber is found between 5 and 17 kilometers (3.1 to 10.6 miles), and the more massive lower chamber is found between 20 and 50 kilometers (12.4 and 31.1 miles) below. The new paper has no issue with that – but wait, there’s more!
Between the more brittle upper crust and its more ductile underbelly, molten material is thought to get bunched up and accumulate. The University of Oregon and ETH Zurich team suggests that, thanks to this boundary, a huge, horizontal magmatic body named a sill – like window sill – has formed, between 10 and 25 kilometers (6.2 and 15.5 miles).