TV vs. Reality: Docudrama 'Supervolcano'

YELLOWSTONE NATIONAL PARK, Wyo. (AP) -- Scientists say the odds of another catastrophic volcanic eruption in Yellowstone within anyone's lifetime are extraordinarily remote, but that's exactly what happens in a made-for-television movie that will air this Sunday.

The docudrama, "Supervolcano,'' will be shown on the Discovery Channel.

The middle of Yellowstone is a huge caldera that last erupted 640,000 years ago. Other huge eruptions occurred 1.3 million and 2.1 million years ago.

Theoretically, the volcano could blow again.

"It's actually quite a well-done movie,'' said Bob Christiansen, former U.S. Geological Survey scientist-in-charge for the Yellowstone Volcano Observatory.

The producers consulted with Christiansen, and he said they worked hard to get the science behind the eruption right.

"It depicts the worst possible scenario that could conceivably happen,'' he said, "and it should be viewed in that light.''

Hank Heasler, park geologist and the park's coordinating scientist for the volcano observatory, said any claim that Yellowstone is overdue for an eruption is based on simplistic reasoning, drawn only from when the three previous known eruptions occurred.

He compared that to predicting the temperature on a certain day in the future based only on the knowledge of temperatures on that day over the past three years.

"It is absolutely absurd to try to predict an interval of eruption,'' he said. "Such a method using just three data points is full of problems. It's the simple way to look at things, but this is not simple.''

Heasler oversees a number of monitoring stations in the park and a range of scientific equipment measuring everything from ground tremors, ground shape, chemical changes in gasses, and water temperatures.

"There will be precursors,'' he said.

Christiansen suspects that the buildup to an eruption would be extended.

"In the movie, the eruptions occur within a few hours,'' he said. "I'd expect the signs and the blast to be longer-term.''

"Supervolcano'' has already aired in the United Kingdom and Christiansen and Heasler have viewed it. Most of the film was shot in Canada.

New Volcano Threat: Just When You Think It's Safe ... Hawaii's Kilauea Volcano Poses Health Risk Hawaii Lava Splashes into the Sea Rumbling Alaskan Volcano Prompts Warning Scientists: Volcano Monitoring Funds Low Image Gallery: The Fury of Volcanoes Image Gallery: Mount St. Helens in 2004 The Science and History of Volcanoes

Geologists Discuss the Docudrama

Editor's Note: The U.S. Geological Survey has put out a Q&A about the docudrama. LiveScience provides it here:

Q: What is the chance of another catastrophic volcanic eruption at Yellowstone?

A: Although it is possible, scientists are not convinced that there will ever be another catastrophic eruption at Yellowstone. Given Yellowstone's past history, the yearly probability of another caldera--forming eruption could be calculated as 1 in 730,000 or 0.00014%. However, this number is based simply on averaging the two intervals between the three major past eruptions at Yellowstone -- this is hardly enough to make a critical judgement. This probability is roughly similar to that of a large (1 kilometer) asteroid hitting the Earth. Moreover, catastrophic geologic events are neither regular nor predictable.

Q: What is a "supervolcano"?

A: The term "supervolcano" implies an eruption of magnitude 8 on the Volcano Explosivity Index, meaning that more than 1,000 cubic kilometers (250 cubic miles) of magma (partially molten rock) are erupted. The most recent such event on Earth occurred 74,000 years ago at the Toba Caldera in Sumatra, Indonesia.

Q: What would happen if a "supervolcano" eruption occurred again at Yellowstone?

A: Such a giant eruption would have regional effects such as falling ash and short-term (years to decades) changes to global climate. The surrounding states of Montana, Idaho, and Wyoming would be affected, as well as other places in the United States and the world. Such eruptions usually form calderas, broad volcanic depressions created as the ground surface collapses as a result of withdrawal of partially molten rock (magma) below. Fortunately, the chances of this sort of eruption at Yellowstone are exceedingly small in the next few thousands of years.

Q: Is Yellowstone monitored for volcanic activity?

A: Yes. The Yellowstone Volcano Observatory (YVO), a partnership between the United States Geological Survey (USGS), Yellowstone National Park, and the University of Utah, closely monitors volcanic activity at Yellowstone. The YVO website (http://volcanoes.usgs.gov/yvo) features real-time data for earthquakes, ground deformation, streamflow, and selected stream temperatures. In addition, YVO scientists collaborate with scientists from around the world to study the Yellowstone volcano.

Q: Do scientists know if a catastrophic eruption is currently imminent at Yellowstone?

A: There is no evidence that a catastrophic eruption at Yellowstone is imminent, and such events are unlikely to occur in the next few centuries. Scientists have also found no indication of an imminent smaller eruption of lava.

Q: How far in advance could scientists predict an eruption of the Yellowstone volcano?

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.

Q: Can you release some of the pressure at Yellowstone by drilling into the volcano?

A: No. Scientists agree that drilling into a volcano would be of questionable usefulness. Notwithstanding the enormous expense and technological difficulties in drilling through hot, mushy rock, drilling is unlikely to have much effect. At near magmatic temperatures and pressures, any hole would rapidly become sealed by minerals crystallizing from the natural fluids that are present at those depths.

Q: Could the Yellowstone volcano have an eruption that is not catastrophic?

A: Yes. Over the past 640,000 years since the last giant eruption at Yellowstone, approximately 80 relatively nonexplosive eruptions have occurred and produced primarily lava flows. This would be the most likely kind of future eruption. If such an event were to occur today, there would be much disruption of activities in Yellowstone National Park, but in all likelihood few lives would be threatened. The most recent volcanic eruption at Yellowstone, a lava flow on the Pitchstone Plateau, occurred 70,000 years ago.

Q: Because Yellowstone is so geologically active, are there other potential geologic hazards in Yellowstone?

A: The heat and geologic forces fueling the massive Yellowstone volcano affect the park in many ways. Yellowstone's many geysers, hotsprings, steam vents, and mudpots are evidence of the heat and geologic forces. These hydrothermal (hot water) features are mostly benign, but can rarely be the sites of violent steam explosions and pose a hydrothermal hazard. Earthquakes, another example of active geologic forces, are quite common in Yellowstone, with 1,000 to 3,000 occurring annually. Most of these are quite small, although significant earthquakes have shaken Yellowstone, such as the 1959 magnitude 7.5 Hebgen Lake quake, the largest historical earthquake in the intermountain region, and the 1975 magnitude 6.1 quake near Norris Geyser Basin. The many earthquakes and steam explosions in the past 10,000 years at Yellowstone have not led to volcanic eruptions.