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Earth Notes

Earth Notes: Drones And Rock Arch Stability


This is Earth Notes.Thousands of visitors from all over the world come to the Colorado Plateau every year to see the area’s famed natural rock arches. But these geologic wonders can be fragile, with dozens of documented collapses since the 1970’s.

For a better understanding of rock arch stability, a team of geologists led by Jeff Moore at the University of Utah wanted to create accurate three-dimensional models of iconic arches like Rainbow Bridge.

The team got their study off the ground by taking to the air. They were able to use drones on certain state and federal lands as a non-invasive way to obtain highly detailed visual representations of many arches across the region.

In national parks like Canyonlands and Arches where drones are banned to lessen noise pollution and disturbances to wildlife, the team hiked to the base of each arch and took photographs using cameras mounted on long poles.

Then, they combined the detailed 3-D models with other environmental data to better understand the vibrational properties of these structures.

When sped up, the models make the stone formations appear to wiggle or dance. These resonant vibrations are stimulated by subtle background movements of the earth, the frequencies changing with ice content and thermal stresses as the rocks heat and cool. The models are being archived to ensure there’s a record for posterity should some of these ancient structures collapse in the future.

Click here to take a virtual tour of the arches: