Beneath Yellowstone National Park (USA), which is located in the northeast corner of the state of Wyoming and part of Montana and Idaho, a beast sleeps: the Yellowstone supervolcano. It is called a supervolcano because its eruptive power can exceed up to 100 times that of a conventional volcano, which is why it is also considered ‘high risk’.
Around 630,000 years ago , a powerful eruption in the region expelled 1,000 cubic kilometers of rock and ash, creating a 64-kilometer-wide volcanic caldera, where most of this famous park sits. It was the birth of the Yellowstone supervolcano . As a result of that eruption, an extensive area of igneous rock was formed, known as the Lava Creek tuff, which is still being studied to find out details about its lethargy and possible awakening.
Now, a new investigation has put it back on the scene, after exposing that the volcano could wake up earlier than expected. Although it is not necessary to give the alarm signal. The researchers, from Arizona State University, presented their findings at the 2017 International Earth Chemistry and Volcanology Association conference in Oregon.
Experts analyzed the fossilized ash deposits taken from the Lava Creek tuff, revealing that Yellowstone’s last major eruption took place when new magma moved into this system just decades before the explosion . It was previously believed that the geological process that led to this event would have taken several millennia.
The sizes of the crystals reflect changes in the temperature of their surroundings, so measuring the different layered crystals can tell us a lot about their history. In this case, the time between a fresh injection of hot magma from deep underground and the eruption was measurable in decades (and not millennia), suggesting that if the supervolcano were to erupt again, we might have much less time to predict it than we thought. .
The last eruption of the Yellowstone caldera was 174,000 years ago, although lava was still flowing until 70,000 years ago.
Could it erupt?
Today, the volcano is relatively quiet, with no looming repeats of tremors. Now, a new map published by the United States Geological Survey (USGS) reports certain deformations in the terrain around Yellowstone in the last two years due to pressure caused by underground tremors: the ground has risen 7 inches in the Norris Geyser Basin and has sunk about 3 inches in the Yellowstone caldera area. This type of activity is normally due to changes in the state of magma and gases far below the surface. But these patterns do not exceed the historical norm, according to experts.
A possible increase in the activity of this caldera poses a great threat, since in the event of an imminent eruption, an unlikely event right now, the potential victims would be millions and the states of Montana, Idaho and Wyoming would become a real hell , not counting the enormous amount of ash that would rise to the atmosphere that would drown the Earth of sunlight for many years, which would amount to a global cooling of the climate ). It would cause real world devastation.
Considering that Yellowstone has had three supereruptions in the last 2.1 million years (the last was in Toba, Indonesia), geologists are taking a closer look at its seismic activity, and considering ways to help the volcano stay cool if it starts to warm up again in the future.
Having a better knowledge about volcanic processes would help to improve predictions and establish possible measures that would save us time.
Reference: IAVCEI 2017 Scientific Assembly / USGS
