Fairbanks Sinkholes Draw in Repair Crews, Theories
Like it has in many other states across the country, the ground near Fairbanks seems to have taken on a life of its own after a recent spate of rain. On campus at the University of Alaska Fairbanks, there are spots where holes swallow up the ground around them.
Casey Stagno has worked on the grounds crew for Facilities Services at UAF for nine years. During his time, he says he's seen sinkholes -- including one from 2007 which went from 2 feet to 15 feet wide in a day.
"You could hear water running through it," Stagno said.
The crew worked quickly to fill in the hole, which sat next to a building and a large fuel tank. It ultimately took 50 dump-truck loads of gravel to do so, and seven years later the hole can't even be located.
A few miles from campus, another hole opened up in a front yard a few weeks ago. Homeowner Al Schultz, who lives in an area called Gold Hill which used to see frequent mining for the precious metal, called B&B Excavation for help.
B&B owner Gary Powell is an expert in moving earth. He's also turned into a bit of an investigator this summer, since the smooth sides of Schultz's sinkhole indicated recent rain may have opened up an old mine shaft. When Powell's crew came to assess the situation, one of the workers tied a bumper hitch to 30 feet of rope.
"He was standing there, holding it casually," Powell said. "Well, it almost yanked it out of his hands."
The crew eventually measured the hole at 82 feet deep.
Stagno at UAF says the grounds crew compares the sinkholes to the whirlpools that swallow ships in Homer's Iliad, the Greek myth retelling the Trojan War.
"It can be pretty intense when the ground opens up out of nowhere -- you wonder where all the material is going," Stagno said.
What causes the ground to move is something that interests Dr. Matthew Sturm at UAF. While sinkholes aren't his specialty, Sturm studies geophysics and says sinkholes get people interested in his line of work.
"My sentiment is that the excitement over potholes come from two things," Sturm said.
One of those is the record amount of rainfall this summer in the Fairbanks area.
"Whether you have ice or an existing hole with fine material, once you start pouring water into it, it can winnow it out," Sturm said. "It can either melt the ice or move that fine sediment in to the ground system."
Sturm says it's important to remember the erosion you see above ground happens below the surface too. For many people though, out of sight is out of mind.
"This whole concept that we're living in a permafrost world that's thawing is lost on people in their day-to-day lives," Sturm said.
What may not be lost is a realization that Alaska's landscape is always changing -- and that includes its geology.
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