Scientists from the University of Utah – a YVO partner agency – recently presented new research at the Fall meeting of the American Geophysical Union in San Francisco that suggests that the size of the magma body beneath Yellowstone is significantly larger than had been thought. Previous similar studies had underestimated the size of the magma body because of insufficient instrumentation. Over the past decade, improvements to the Yellowstone monitoring network has increased the number and quality of the instruments deployed. This new research takes advantage of these upgrades, which will continue to pay dividends for years to come.
The UU researchers, in collaboration with a scientist from the Swiss Seismological Service in Zurich, used a method called seismic tomography to create an improved image of the magmatic system beneath Yellowstone. One should not think of Yellowstone’s magma reservoir as a big cavern full of churning lava. Rather, the reservoir is distributed throughout a porous, sponge-like body of otherwise solid rock, with the amount of liquid rock (melt) varying from place to place. Because seismic waves slow down when traveling through liquids, seismic tomography can be used to map out these variations. The new research shows that while the magma reservoir is bigger than we thought, the proportion of melt to solid rock (estimated at <10-15%) is similar to previous reports and appears to remain way too low for a giant eruption.
Although fascinating, the new findings do not imply increased geologic hazards at Yellowstone, and certainly do not increase the chances of a “supereruption” in the near future. Contrary to some media reports, Yellowstone is not “overdue” for a supereruption. Indeed, it is quite possible that such an eruption will never again occur from the Yellowstone region. Scientist agree that smaller eruptions are likely in the future, but the probability of ANY sort of eruption at Yellowstone still remains very low over the next 10 to 100 years.
YVO scientists from organizations around the country continually monitor geologic conditions at Yellowstone. At present those conditions are normal and there is no heightened concern for public safety. Should conditions change, an established alert system will quickly notify public officials, the general public, and the media. YVO posts regular updates about activity at Yellowstone, which can be found on the activity update webpage. We encourage you to explore our website for additional information on geologic hazards and current activity at Yellowstone.
Repeating earthquakes suggest volcanic and tectonic origins of Yellowstone seismic swarms
June 06, 2013
In a study published in 2013, University of Utah seismologists studied patterns of earthquakes at Yellowstone, grouping events according to similarity of their ground motion records. They found that some earthquakes appear to repeat over time, while others are unique. This research indicates that repeating earthquakes are dominantly tectonic in origin, whereas the more unique earthquakes may be induced by intrusion of molten rock or hot pressurized ground (hydrothermal) water along pre-existing fractures. Read more in our online web article or, for greater detail, read the full research manuscript.
Sloshing Detected in Yellowstone Lake Helps to Locate Magma Storage Region
March 20, 2013
USGS postdoctoral fellow Karen Luttrell, together with colleagues from UNAVCO and elsewhere, recently published an article in Geophysical Research Letters (GRL) revealing how the presence of magma beneath the ground at Yellowstone allows the deformation signal from a standing wave (seiche – pronounced “say-sh”) in Yellowstone Lake to travel further than it would in the earth’s crust under normal (magma-free) conditions. Highly sensitive instruments picked up the seiche signal up to 30 km (19 mi) from Yellowstone Lake when the signal would typically only be observed within a few kilometers. The authors estimate that magma is present starting at 3—6 km (2—4 mi) beneath the ground surface, and that the magma is mostly crystallized but is still partly molten. Read our web article to learn more, or download the full research paper at the GRL website.
Yellowstone quick facts
Location: Wyoming and Montana
Latitude: 44.615° N
Longitude: 110.6° W
Elevation: 2,805 (m) 9,203 (f)
Volcano type: Caldera
Composition: basalt to rhyolite
Most recent eruption: 70,000 years ago—lava, current—hydrothermal explosions