Geologists reexamined Yellowstone’s subsoil and detected more magma than expected. What does this mean for the supervolcano’s immediate future?
The eruption of a supervolcano is one of the most powerful natural catastrophes on Earth, the consequences of which can devastate entire continents. One such danger lurks beneath Yellowstone National Park in the United States. Yellowstone is one of the largest supervolcanoes in the world, having erupted on a large scale at least three times in the past 2.1 million years, spanning across North America. of ash and rocks. In the meantime, small eruptions occurred; the last one occurred about 70,000 years ago, when lava flowed through the caldera.
A team led by Ross Maguire of the University of Illinois Urbana-Champaign measured the volume and composition of the monster’s magma chamber and now presented the results in the prestigious journal Science🇧🇷 According to the research group’s analysis, the molten rock deposit contains twice the amount of previously known magma. Although, it does not mean that an eruption has become more likely.🇧🇷 According to scientists, this is related to the composition of the material in the magma chambers. Yellowstone is fed by two chambers, one close to the mantle and the other a few kilometers below the surface. Both contain a mix of fully molten rock and partially crystallized material.
The composition of this mud helps determine the probability of the supervolcano erupting: the greater the ratio of molten rock to solid crystals, the more likely it is that magma will rise and the volcano will erupt. So Maguire and company analyzed Yellowstone seismic data from the past 20 years to determine the proportion of both materials in the upper magma chamber. They took advantage of the fact that seismic waves travel more slowly through sections with more molten rock than through firmer and therefore “harder” areas.
The researchers fed the data into a computer model to create a three-dimensional image of the chamber and the waves passing through it. Previous studies used only linear models. As a result, geologists have determined that the magma chamber is composed on average between 16% and 20% molten rock, whereas previous estimates only hit a figure of 9%. Converted, that’s about 1,600 cubic kilometers of magma, almost double the previous estimate of around 900 cubic kilometers.
However, there is no threat of an eruption in the immediate future, Maguire wrote. Even the highest estimate is still well below the 35 to 50 percent ratio of magma needed for an eruption, he said. “Yellowstone can spend a large part of its life cycle with some melting without an eruption”, says the scientist. However, when the time comes, there is almost no prep time. According to studies, the first signs of a rash probably appear just a year earlier.
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Magma buildup deep in former rhyolite storage below Yellowstone Caldera