Magma reservoirs under the Yellowstone supervolcano began to shift towards the poorly studied northeastern part of the park. This is stated in a paper published in the journal Nature.
A team of US geologists led by Clifford Thurber, a professor at the University of Wisconsin in Madison, USA, found that this region of the volcano has accumulated about as much magma today as it did before its major eruption 1.3 million years ago.
‘Our measurements indicate that basaltic masses from the lower crustal strata have recently begun to move toward, merge with, and further warm the rhyolitic magma accumulations in the northeastern part of Yellowstone Park. This indicates that the centres of future explosive volcanism have moved to this region of the current caldera of this supervolcano’, – stated in the article.
The conclusions are based on data collected in Yellowstone National Park using seismographs and magnetotelluric Earth sensing systems. These instruments track the movement of magma by changes in the electrical and magnetic properties of different layers of the crust.
Scientists recently installed more than a hundred such sensors in Yellowstone Park to create the first detailed map of magma reservoirs and observations of magma movements in the upper and lower crust. They used the collected materials to create a three-dimensional model of the network of magma chambers located beneath the Yellowstone supervolcano at depths ranging from 2 kilometres to 40 kilometres.
In total, the researchers were able to detect seven large magma reservoirs, some of which are actively filled with rocks from the rhyolite class, capable of generating powerful explosive eruptions. A significant portion of these growing magma chambers are located in the northeastern part of the current caldera of Yellowstone volcano, which was previously considered quiet and because of this has been little explored.
The magma chambers here contain about 440 cubic kilometres of hot rhyolitic rocks, which is an order of magnitude larger than their reserves in other parts of the caldera. In this respect, the northeastern magma reservoirs are comparable to the amount released from Yellowstone 1.3 million years ago, during one of the supervolcano’s three giant eruptions. This makes the region particularly important for assessing the potential threat of Yellowstone to civilisation, the scientists concluded.
Recall, on the territory of Yellowstone National Park is one of the largest supervolcanoes of the Earth with high geological activity. The last time he awakened about 650-700 thousand years ago. This led to large-scale fires in North America and to a sharp cooling of the Earth’s climate as a whole.