Yellowstone Animals Fleeing Park — Supervolcano Eruption Imminent?

If you listen to some animal experts, that answer is a definitive "yes".

Recall, if you will, the tsunami in late 2006. Do you remember reports that animals were escaping and running for higher ground hours before the waves hit? This mass animal evacuation brought into light the instinct which biologists have known about for years which seems to tell animals when disaster is about to strike.

At Yellowstone National Park in Wyoming, there is a mass animal exodus underway. Miles of buffalo can be seen running frantically from the Northwest end of the park. They are even running down roads. Elk are also evacuating at an astounding rate. Smaller animals such as rabbits and squirrels are also fleeing Yellowstone.

"Those bison were running for the sake of running," Leckie said in an interview. "There was nothing chasing them. There was no mudslide. They were just running."

Added Leckie: "And they were running into the park, not away from it."

What about other animal trends? In NATURE's Can Animals Predict Disaster?, for instance, one geologist

says he sees an increasing number of missing pets documented in the local classified ads just before an earthquake strikes in California. He, in fact, predicted the famous San Francisco earthquake of 1989. The theory is that the animals are fleeing the impending quake.

Again, other scientists doubt this. USGS scientists, for instance, say even simple science fair projects will show little statistical association.

Similarly, scientists are skeptical that any special "sixth sense" helped animals survive the great tsunami that swept the Indian Ocean in 2004. After the wave, people reported seeing animals fleeing to forests on high ground and finding few bodies of dead animals. But scientists note that little hard data exists, and that many animals may have survived simply because they are strong swimmers or able to scamper up trees.

We should be careful not to give animals super-powers, says Whit Gibbons, an ecologist at the University of Georgia. "I always like stories of animals outsmarting humans, [but] I really don't think animals have any special powers beyond those that help them in their daily lives," writes Gibbons. "I do not doubt that many animals detect certain natural signals, such as the early tremblings of an earthquake, long before humans. This means they have opportunity to react before we can. But to think they are reacting any differently from someone who runs for an exit at a shout of 'fire' is to give wildlife more credit than is deserved."

Seismologists with the University of Utah emphasized that the recent quake doesn't signal an impending eruption of the Yellowstone supervolcano, also known as the Yellowstone Caldera.

Most researchers agree that the Yellowstone supervolcano will erupt again, including Ilya Bindeman, an associate professor of geological sciences at the University of Oregon.

However, Bindeman says he doesn't think that this kind of eruption will happen anytime soon. He says it won't happen for at least another million years.

"Our research of the pattern of such volcanism in two older, 'complete' caldera clusters in the wake of Yellowstone allows a prognosis that Yellowstone is on a dying cycle, rather than on a ramping up cycle," he says.

A: No. First of all, one cannot present recurrence intervals based on only two values. It would be statistically meaningless. But for those who insist ... let's do the arithmetic. The three eruptions occurred 2.1 million, 1.3 million and 0.64 million years ago. The two intervals are thus 0.8 and 0.66 million years, averaging to a 0.73 million-year interval. Again, the last eruption was 0.64 million years ago, implying that we are still about 90,000 years away from the time when we might consider calling Yellowstone overdue for another caldera-forming eruption. Nevertheless, we cannot discount the possibility of another such eruption occurring some time in the future, given Yellowstone's volcanic history and the continued presence of magma beneath the Yellowstone caldera.

Q: When will Yellowstone erupt again?

A: We do not know. Future volcanic eruptions could occur within or near Yellowstone National Park for the simple reason that the area has a long volcanic history and because there is hot and molten rock, or magma, beneath the caldera now. Yellowstone is monitored for signs of volcanic activity by YVO [Yellowstone Volcano Observatory] scientists who detect earthquakes using seismographs and ground motion using GPS (Global Positioning System). YVO has not detected signs of activity that suggest an eruption is imminent.

The crust of North America continuously moves southwest over the Yellowstone hotspot as the Earth's crust stretches above it, promoting the ascent of heat and molten rock. These processes produce basaltic magmas within the Earth's mantle, which rise into the overlying crust and continue to heat the rocks beneath Yellowstone, maintaining and possibly adding to the rhyolite magma in the crust above.

Yellowstone's 2-million-year history of volcanism, the copious amount of heat that still flows from the ground, the frequent earthquakes, and the repeated uplift and subsidence of the caldera floor also testify to the continuity of magmatic processes beneath Yellowstone and point to the possibility of future volcanism and earthquake activity.

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.

The most likely activity would be lava flows such as those that occurred after the last major eruption. Such a lava flow would ooze slowly over months and years, allowing plenty of time for park managers to evaluate the situation and protect people. No scientific evidence indicates such a lava flow will occur soon.