Yellowstone caldera - The power to surprise

The Journal of Geophysical Research has come up with some fascinating new findings on the Yellowstone super-volcano and the nearby Grand Teton mountains.

First, it seems the Yellowstone caldera has seen its share of ups and downs in recent years, including a 7-inch rise from 2004 to 2006. That's unprecedented, which may not mean a whole lot given the limited time that man has actually studied it, and considering that the last big eruption was 630,000 years ago. Still, geologists are cautiously wondering if the game is, er, under foot, so to speak.

The 45-by-30-mile caldera bulged and deflated significantly during the study period, resulting in a series of small earthquakes that produced 10 times more energy than would occur if the ground were to move suddenly in a large eruption.

"We think it's a combination of magma being intruded under the caldera and hot water released from the magma being pressurized because it's trapped," said lead study author Robert Smith from the University of Utah. "I don't believe this is evidence for an impending volcanic eruption, but it would be prudent to keep monitoring the volcano."

We most certainly want him to be prudent.

But there's a second aspect to their findings: the Grand Teton mountain range to the south and west of the caldera is losing height. The fault line that runs north-south is showing abnormal characteristics.

Typically, when a big earthquake takes place on a normal fault such as the Teton, the ground is pulled apart.

This kind of extension or stretching causes valleys to drop downward and mountains to rise upwards. Thousands of earthquakes over millions of years built the mountains that comprise the Teton Range today.

But recent measurements showed a different trend.

Researchers found that just the opposite is happening with Jackson Hole — the valley below the Teton. The valley is rising up slowly and the mountains are dropping down.

What the researchers think is happening, on a short-term basis at least, is that the bulging Yellowstone hotspot north of the Tetons is pushing against the north edge of Jackson Hole and jamming it against the mountains.

(This is also causing the southwest part of the Yellowstone plateau, under the hotspot, to slide downhill at a rate of one-sixth of an inch each year.)

"The textbook model for a normal fault is not what's happening at the Teton fault," Smith said. "The mountains are going down relative to the valley going up. That's a total surprise."

Scientists think it means bigger quakes in the future. No one is saying "the Big One" because no one wants to sound crazy, and that's understandable. The Big One could take place anytime between tomorrow and 100,000 years from now. Still ...

Not that it matters much, but we do not care for the phrase "that's a total surprise" when it is associated with a super-volcano that has the capability of ruining a perfectly good day for two-thirds of America, not to mention our Canadian neighbors. It could cause less secure minds to worry senselessly.

Which is why we thought we'd quote a bit of scripture to provide you with some comfort, a portion of Isaiah that seems especially appropriate:

A voice cries out: In the desert prepare the way of the Lord! Make straight in the wasteland a highway for our God! Every valley shall be filled in, every mountain and hill shall be made low; The rugged land shall be made a plain, the rough country, a broad valley. Then the glory of the Lord shall be revealed, and all mankind shall see it together, for the mouth of the Lord has spoken. (Is. 40:3-5)