Alaska Homeowner Fills 8-Story Mystery Sinkhole

Geophysicists don’t know what caused a sinkhole measuring about 80 feet deep to appear in a Fairbanks, Alaska resident’s yard last week.

And they might never know. Homeowner Al Schultz had safety concerns about the hole, which measure about 4 feet wide and up to eight stories deep so he had it filled Monday with five truckloads of gravel.

The Fairbanks Daily News-Miner reported that happened before two university geophysicists arrived.

Matthew Sturm, with the University of Alaska Fairbanks’ Geophysical Institute, did watch a shaky video of the hole produced by the newspaper. From that, Sturm says the hole didn’t appear to be man-made, discounting a theory that it was an abandoned mining shaft.

Instead, he thinks it was a fissure created by ice which has melted away.