Yellowstone supervolcano mapping reveals scale of future eruptions: 'Things can change within...'

An underground map of the supervolcano at the Yellowstone National Park has revealed something astonishing about the park's subsurface. USGS researchers collaborated with Oregon State University and the University of Wisconsin-Madison and mapped the subsurface of Yellowstone in an entirely new way. Using electromagnetic imaging, they captured shifts in the Earth’s natural electromagnetic field. Such changes are triggered by lightning or solar storms. The process is called magnetotellurics and can detect how well rocks conduct electricity. Molten rock is more conductive than solid, and so the method revealed the location of magma. Four distinct magma reservoirs were discovered under the caldera. All of them are located around 4 and 11 kilometers under the caldera and are made of rhyolitic magma.

Such magma is rich in silica and erupt violently in the future. The pockets found vary in size and shape, but one of them is extremely familiar. This particular one contains almost the same volume of magma that was released during Yellowstone’s Mesa Falls eruption. This episode occurred 1.3 million years ago and changed the landscape of Yellowstone. Scientists have shifted their focus from the central and western parts of the caldera, and moved to the northeast. This place has thrown up some starling results as a link has been established between shallow rhyolitic magma and deeper basaltic heat. Also Read: 425 volcanoes, two years: Ring of Fire can become a blazing string of lava very soon

What basaltic magma does is it releases more heat that can melt more rock and also links the reservoirs. The USGS has warned that the magma in this system could grow immensely over hundreds of thousands of years. Meanwhile, in the western side of the caldera, the magma is cooling and becoming solid, and so is not expected to erupt. Scientists have been watching this supervolcano in Yellowstone, stating that eruption might not be imminent. However, “things can change in decades, not just millennia,” Larry Mastin, a volcanologist at the USGS, said. Also Read: From Pangea to brutal Amasia: Earth stares at its next mega continental mash-up

What would happen if Yellowstone volcano erupts?

Yellowstone has erupted three times in the last 2.1 million years, and each time has not only altered the region, but also the global climate. Scientists say if it were to erupt again, a catastrophic scene would unfold. Smaller explosions would lead to a sudden release of pressure. A VEI 8 super-eruption will send ash plumes into the stratosphere within minutes, and an area of 100-kilometre radius could be affected immediately. Mastin says much of North America would be hit, with Chicago, San Francisco and even parts of eastern Canada witnessing huge ash deposits. Sulfur dioxide will reach the upper atmosphere, blocking the Sun and cooling the planet. This cooling could last 15–20 years, and devastate the climate, crops, weather and the ecology.