New evidence on Yellowstone's volcanic activity might shed light on the long-debated theory on the presence of magma plume beneath the national park.
The Yellowstone caldera is a complex system of rock formations that sprung after a series of volcanic eruptions some 630,000 million years ago. This is the widely accepted theory, although there are some scientists who argue that the national park sits right on top of a "hot spot."
Results of the investigation conducted by Peter Nelson and Stephen Grand from the University of Texas' Jackson School of Geosciences supports the latter theory suggesting a massive magma plume beneath the park's surface. This plume, which is the technical word for a magma foundation, appears to extend as far as Mexico.
How Plumes Are Formed
In a geographic sense, a plume is an abnormality that exists when the earth's core rises through the mantle forming what it appears to be a foundation of hot magma.
The study, which was published in Nature Geoscience, reported that the probability of a magma plume underneath Yellowstone could explain the heat that influences ground activities such as the Boiling River. This latest claim debunks earlier explanations that the heat source is a by-product of lithospheric movements.
Nelson and Grand's team gathered seismic data using EarthScope's USArray, which showed a "long, thin, sloping zone" that measured about 72 kilometers long and 55 kilometers wide. Because seismic patterns travel slower in this region of the mantle, it is understandable that it can be up to 800 degrees Celsius higher than its surrounding areas.
The emerging image revealed a 350-kilometer cylinder formation that runs all the way to the California-Mexico border.
Magma Plumes Around The World
In the case of Hawaii, plumes are formed when the ocean plate moves beneath land masses in a process called subduction. Rocks could get in the way during the process, then forming the plumes which are fixated on earth.
"There are many suspected plumes, or hot spots, around the Earth. Yellowstone is one of them, but it's a bit more complex," said Michael Poland, a scientist at the Yellowstone Volcano Observatory.
According to Polan, although the science of plumes seems complex, it has always been there posing itself as a natural geographic occurrence.
"[Plumes have] no impact on our understanding of how Yellowstone works in terms of eruptive cycles, just their driving forces. It doesn't change our perception of volcanic activity at all," Poland explained.