The likelihood of a volcanic supereruption from Yellowstone, or any other location on Earth, remains very low in any given year, yet the U.S. Geological Survey is frequently asked about the likely thickness and distribution of ash deposits if Yellowstone were to erupt. This prompted USGS scientists to use a new computer model called Ash3D to simulate the distribution of volcanic ash from a hypothetical large explosive eruption at Yellowstone. A research paper explaining the results was published in Geochemistry, Geophysics, Geosystems on August 27, 2014, and we have developed some FAQ to help explain the background to this study.
The researchers discovered that during very large volcanic eruptions, ash transport is dominated by a rapidly expanding umbrella cloud that results in significant distribution of ash upwind from the volcanic vent. "In essence, the eruption makes its own winds that can overcome the prevailing westerlies that normally dominate weather patterns in the United States," explained USGS geologist Larry Mastin, first author on the manuscript and co-developer of the computer model. "This helps explain the distribution from large Yellowstone eruptions of the past, where considerable amounts of ash reached the west coast." The authors also note that a fraction of an inch or less of ash is likely to be deposited at distances further than 1500 miles, such as on the east and west coasts of the United States. To learn more, please read our Frequently Asked Questions about the model and its application to Yellowstone.
Though we love doing research at YVO, we prefer it when the research is on topics geological rather than the origin of false rumors. Nevertheless, we have received enough concerned emails and phone calls that we've spent some time tracking down a few of the statements made on various "alternative Internet news sources."
1) First, everyone should know that geological activity, including earthquakes and ground uplift/subsidence is well within historical norms and seismicity is actually a bit low at present.
2) Concern over road closures is much overblown. There's been one road closure of a small side road – just over three miles long – that was closed for two days. As one can imagine, it is not easy to maintain roads that pass over thermal areas where ground temperatures can approach those of boiling water. Roads at Yellowstone often need repair because of damage by thermal features as well as extreme cold winter conditions.
3) The park has not been evacuated. This one is pretty easy to verify by everyone. If the Old Faithful webcam shows people, or if news articles are coming out about a hobbyist's remote control helicopter crashing into a hot spring, Yellowstone is certainly open for business.
4) No volcanologists have stated that Yellowstone is likely to erupt this week, this month or this year. In one recent article, a name was attributed to a "senior volcanologist", but that person does not appear to exist, and a geologist with that name assures us that he did not supply any quotes regarding Yellowstone.
5) Finally, we note that those who've kept track of Yellowstone over the past decade or so, have seen a constant stream of "predictions" regarding imminent eruptions at Yellowstone. Many have had specific dates in mind, none had a scientific basis, and none have come true.
We will continue to provide updates on geological activity at Yellowstone, and educational materials to help understand the science around Yellowstone monitoring.
Virtually everything known about Yellowstone's spectacular volcanic past comes from the scientists who work at this observatory, at all our eight member agencies. We're the ones who mapped the deposits, figured out the ages of the eruptions, measured the gases, located the earthquakes, and tracked the ground movement. A few of us have been doing it for over forty years. We will continue to help you understand what's happening at Yellowstone now, and what's likely to happen in the future.
How do we know what's beneath Yellowstone, and how can we image the shallow magma? Seismologists at the University of Utah (a YVO member agency) and the Swiss Federal Institute of Technology undertook a study to image the Yellowstone magma reservoir through a technique called seismic tomography. Using improved methods and data from thousands of earthquakes; they discovered that the magma reservoir is much larger than inferred in previous studies. Read our website article to find out how the study was conducted and what they discovered. The complete results from this new approach are published in the Journal Geophysical Research Letters.