Q: How imminent is an eruption of the Yellowstone Volcano?

A: There is no evidence that a catastrophic eruption at Yellowstone National Park (YNP) is imminent. Current geologic activity at Yellowstone has remained relatively constant since earth scientists first started monitoring some 30 years ago. Though another caldera-forming eruption is theoretically possible, it is very unlikely to occur in the next thousand or even 10,000 years. Scientists have also found no indication of an imminent smaller eruption of lava.

Q: How much advance notice would there be of an eruption?

A: The science of forecasting a volcanic eruption has significantly advanced over the past 25 years. Most scientists think that the buildup preceding a catastrophic eruption would be detectable for weeks and perhaps months to years. Precursors to volcanic eruptions include strong earthquake swarms and rapid ground deformation and typically take place days to weeks before an actual eruption. Scientists at the Yellowstone Volcano Observatory* (YVO) closely monitor the Yellowstone region for such precursors. They expect that the buildup to larger eruptions would include intense precursory activity (far exceeding background levels) at multiple spots within the Yellowstone volcano. As at many caldera systems around the world, small earthquakes, ground uplift and subsidence, and gas releases at Yellowstone are commonplace events and do not reflect impending eruptions.

*The YVO is a collaborative effort between the US Geological Survey, the University of Utah, and YNP to monitor and study the Yellowstone Volcano. Congress has given the USGS the responsibility of volcano hazard assessment, and YNP assists the USGS in their volcano monitoring effort.

A: Yes. Scientists do not have any indication of an imminent eruption, or any eruption, at this time.

Q: What is park staff doing to monitor and assess the probability of an eruption?

A: The YVO maintains an array of instruments that monitor activities at Yellowstone around the clock. In addition, YVO scientists collaborate with scientists from all over the world to study and assess the hazards of the Yellowstone volcano. To learn more about Yellowstone's volcanic past and to view current data about earthquakes, ground movement, and stream flow, visit the YVO website at http://volcanoes.usgs.gov/yvo/.

Q: When will the volcano erupt again? Will there be any warning? How much warning will there be?

A: The science of forecasting a volcanic eruption has significantly advanced over the past 25 years. Most scientists think that the buildup preceding a catastrophic eruption would be detectable for weeks and perhaps months to years. Precursors to volcanic eruptions include strong earthquake swarms and rapid ground deformation and typically take place days to weeks before an actual eruption. Scientists at the YVO closely monitor the Yellowstone region for such precursors. They expect that the buildup to larger eruptions would include intense precursory activity (far exceeding background levels) at multiple spots within the Yellowstone volcano. As at many caldera systems around the world, small earthquakes, ground uplift and subsidence, and gas releases at Yellowstone are commonplace events and do not reflect impending eruptions.

Q: Is the volcano dormant or extinct or still active?

A: The Yellowstone Volcano is still active. Evidence for the activity of the Yellowstone Volcano are the 1,000 to 3,000 earthquakes per year, active ground deformation, and the over 10,000 thermal features found in Yellowstone.

Q: What is Yellowstone doing to prevent an eruption?

A: Nothing can be done to prevent an eruption. The temperatures, pressures, physical characteristics of partially molten rock, and the immensity of the magma chamber are beyond man's ability to influence--much less control.

Q: How will the park get the word out if there is an eruption?

A: The park would communicate accurate and timely information to park visitors, park employees, concessioners, surrounding communities, media outlets, and other interested parties through the park's 24-hour Communications Center; news releases; established emergency response programs; and through notification of appropriate interagency, state and local government agencies.

Q: Where would it be safe to be during an eruption?

A: For the most likely type of volcanic eruption in Yellowstone, everywhere would be safe except in the immediate vicinity of the advancing lava flow. In the highly improbable event of a large catastrophic eruption, the greater the distance from the eruptive center, the safer it would be. It is impossible to know the effects of the eruption without guessing at the explosivity of the highly unlikely eruption and the total amount of the material erupted.

Q: Would the public know about a possible eruption?

A: Yes. Scientists continuously monitor volcano activity in Yellowstone and share that information through news releases, web sites, etc. Current real-time-monitoring data are online at http://volcanoes.usgs.gov/yvo/monitoring.html.

Q: If Old Faithful quits erupting, is that a sign the volcano is about to erupt?

A: Geysers are natural phenomena and as such, their behavior is unpredictable and subject to unexpected changes. Old Faithful is unique in that its eruptions have been frequent and relatively consistent during the last century or so of observations. We expect Old Faithful to change in response to the ongoing geologic processes associated with mineral deposition and earthquakes. Thus, a change in Old Faithful Geyser's eruptions will not necessarily indicate a change in volcanic activity.