In Goblin Valley, chances of getting hurt by a falling rock are slim
By Janelle Stecklein
The Salt Lake Tribune
First published Oct 22 2013 05:53PM
The hypothetical family that a group of Highland men allegedly was trying to protect when they destroyed a rock structure was more likely to die on the drive to Goblin Valley State Park than to be crushed by a falling rock.
That’s at least according to an unrelated study conducted by the National Safety Council’s Injury Facts 2013 edition that crunched one’s odds of death based on 2009 statistics.
In the course of a lifetime, a person had a 1 in 5,180 chance of dying by being struck by or striking against an object. The National Safety Council classifies death by falling rock in that category.
That’s compared with a 1 in 108 chance of dying in an automobile accident. Or a 1 in 749 chance of getting hit by a car.
David Hall and Glenn Taylor drew worldwide attention after they posted a video of Taylor pushing over a rock formation known as a "goblin" earlier this month while leading a Boy Scout troop on an outing. The two men said on the video that their actions would save an unsuspecting family from getting crushed beneath the large rock.
While no charges have been filed, officials are conducting a criminal investigation and said the men could face prosecution for destroying the formation. The two men already have been kicked out of the Boy Scouts for their actions.
Both men said that the rock was loose and a safety hazard to the public, which they fixed by knocking over.
"There are very few national and state parks in Utah where there are no rockfall hazards," said Richard Giraud, a senior geologist with the Utah Geological Survey, Geologic Hazards Program, which works with the state and national parks across Utah to help mitigate risk from people being injured by falling rocks.
"The park is there because of its scenic value and unique geologic features that may have an associated rockfall hazard," he said. "It’s rare that you would just remove the geologic feature and associated hazard. That feature is why the park is there. It’s better to preserve the feature and keep people a safe distance from the hazard."
Sometimes that involves rerouting tourists around dangerous spots where they could be at risk and placing an interpretive sign or barring access to an area.
"There are a lot of different ways to manage rockfall hazards," Giraud said. "Highway departments do it continually." If people have a concern about whether a rock formation is safe, he said, they should alert a park ranger and let professionals address it rather than take matters into their own hands.
That’s in part because other than being neat to look at, many rocks like the Goblin Valley formation serve a dual purpose.
Glenn Biasi, an associate research professor at the University of Nevada, Reno, uses similar rocks, known as precariously balanced rocks, to study earth movements in Nevada and California along the San Andreas Fault.
If a rock has been in place for centuries or millennia, he said, "it gives you an estimate of how hard the ground is shaking nearby."
The studies allow officials to evaluate long-term shaking hazards, which can help determine where to build structures such as nuclear power plants.
"What the Goblin Valley hoodoos are showing is no big earthquakes nearby for thousands of years probably," Biasi said. "Around there, strong, ground-shaking earthquakes are exceptionally rare."
He said most of the rocks have mud stone bases, and it wouldn’t be hard to destroy a weaker formation like the two Highland men are accused of doing.
"If you went out with a fire hose," he said, "you could probably knock some of those things over."
Biasi said it likely takes hundreds to thousands of years for formations like the goblins to form out of rocks millions of years old.
He said the rocks are buried most of their lives, but when drainage develops, it starts to wash around them and into cracks, helping create the "precarious rocks" sitting on pillars of softer rock.
Nature allows only the most perfect of the creations to survive into what are known as modern-day goblins, he said. If a rock is too small, the wind will knock them over. The rock itself has to be big enough to protect the pedestal it sits on.
"If they get really, really big," he said, "they become national park things."