Underneath the hot springs and bubbling geysers of the wilderness recreation area in Wyoming sits a volcanic hot spot that brought about some of the largest eruptions on Earth. Geoscientists have now discovered a second magma reservoir underneath the Yellowstone National Park with enough partly molten rock to fill the Grand Canyon 11 times over. Scientists had already known about the volcanic plume that exists under the park but a recent study confirms a second magma chamber which is much wider and deeper.
According to a report by USA Today, the study was published on Thursday, April 23, 2015 in the journal Science. The head of the research team, Hsin-Hua Huang of the University of Utah said that this is the first time they have imagined the continuous volcanic plumbing system under Yellowstone. The newly discovered magma chamber is located about 12 to 28 miles beneath the Yellowstone National Park.
The huge bowl-shaped collapsed volcano is one of several large and active volcanoes in the U.S. It last erupted about 640,000 years ago. Robert B. Smith a geologist at the university of Utah and co-author of the study said that if this supervolcano erupted today, the results would be cataclysmic. Fortunately, there is only one chance in 700,000 of an eruption in any given year.
The discovery does not indicate a greater chance of an eruption. Today, the threat of earthquakes is far more likely. Scientists emphasize that the volcano is no closer to erupting than before. They have just used advanced technique to get a complete image, and in the process discovered an even bigger magma reservoir underneath the Yellowstone National Park.
Science Mag reveals that a deeper magma chamber means that the shallow chamber can be refilled several times. Victor Tsai, a geophysicist at the California Institute of Technology in Pasadena said that the additional reservoir tells that there could be a much bigger volume erupt over a relatively short time scale. The study confirms a long-suspected model of some volcanoes where a deep chamber rich with magnesium and iron, feeds a shallower chamber containing lighter silicon-rich rock.
Scientists used seismometers to record earthquake noise. When tremors pass through liquid, seismic waves slow down. The low-velocity regions are interpreted as molten rock chambers. Distant quakes are useful for imaging deep structures and local tremors help to study shallow chambers. For this study at the Yellowstone National Park, researchers used 69 seismometers from several local seismic networks and 11 seismometers from the EarthScope USArray.
According to The Guardian, the national park, which straddles the borders of Wyoming, Montana and Idaho, sits atop a supervolcano that has had three calamitous eruptions. The eruptions are believed to have occurred around 1.2 million, 2 million and 640,000 years ago. Scientists already knew of a huge magma chamber that fed the past eruptions. The new study published last week in Science revealed a second, deeper reservoir, 4.5 times larger, underneath the Yellowstone National Park.
By Anila M.