Under Yellowstone National Park (USA), which lies in the northeast corner of the state of Wyoming and part of Montana and Idaho, sleeps a beast: the Yellowstone supervolcano. It has the name of supervolcano because its eruptive power can surpass up to 100 times that of a conventional volcano, reason why also it is considered of ‘high risk’.
About 630,000 years ago, a powerful eruption in the region expelled 1,000 cubic kilometers of rock and ash and created a 64-kilometer volcanic caldera, where most of this famous park is located. It was the birth of the Yellowstone supervolcano. As a result of that eruption, a large area of igneous rock, known as the Lava Creek tuff, was formed, which is still being studied to find out details of its lethargy and possible awakening.
Now, a new investigation has returned to put it in scene, after exposing that the volcano could wake sooner than expected. Although it is not necessary to give the alarm signal. The researchers, from Arizona State University, presented their findings at the conference of the International Association of Volcanology and Earth Chemistry of 2017 in Oregon.
The experts analyzed the fossilized ash deposits taken from the Lava Creek tufa, revealing that the last major eruption of Yellowstone occurred when the new magma was moved to this system only decades before the explosion. Previously it was believed that the geological process that led to this event would have taken several millennia.
The sizes of the crystals reflect the changes in the temperature of their environment, so that the measurement of the different crystals in layers can tell us a lot about their history. In this case, the time between a fresh injection of hot magma from underground depth and eruption was measurable in decades (and not millennia), suggesting that if the supervolcano breaks out again, we could have much less time to predict it than we thought .
The last eruption of the Yellowstone caldera was 174,000 years ago, although lava still flowed until 70,000 years ago.
Could it erupt?
Nowadays, the volcano is relatively calm, with no impending repetitions of tremors. Now a new map published by the Geological Survey US Geological Survey (USGS) reports certain deformations experienced in the surrounding terrain to Yellowstone in the last two years due to the pressure caused by the tremors underground: e l land has risen 7 centimeters into the Norris Geyser Basin and has sunk about 3 centimeters into the Yellowstone boiler area. This type of activity is usually due to changes in the state of the magma and gases that are far below the surface. But these patterns do not exceed the historical norm, according to experts.
A possible increase in the activity of this boiler is a great threat, since in the case 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 ascend to the atmosphere that would drown Earth’s sunlight for many years, which would amount to a global cooling of the climate). It would cause real world devastation.
Given that Yellowstone has had three super-errations over the last 2.1 million years (the last one was in Toba, Indonesia), geologists are observing their seismic activity in detail, and considering ways to help the volcano maintain its freshness if it begins to to warm up again in the future.
Having a better knowledge about the volcanic processes would help to improve the predictions and to establish possible measures that would make us gain time.