Crack seen in hill after 5.1 earthquake in North Carolina. Origin of it remains vague

Update: The origin of the gash in the hillside remained vague Tuesday, with some saying it may predate the earthquake Sunday. The exact location has not been revealed.

Travis Simpson-Hunt describes a scene out of a disaster movie, when he recalls birds suddenly taking flight seconds before a 5.1 earthquake rocked Sparta, North Carolina, Sunday.

“It was like a train going through the cabin,” he posted on Facebook.

But more disturbing is what his family saw outside of town that morning, when they went to check out damage reports.

Cars were suspiciously parked along the side of the road — in the middle of nowhere — and Simpson-Hunt pulled over and noticed everyone’s attention was focused on a hillside.

“There was this big one (crack) and a small one below it. And then lots of cracks the width of my foot going across the road,” Simpson-Hunt told McClatchy News. “It was not far outside of town.”

It was the last thing he needed to see to convince him the family’s vacation was over. They packed up after only one day in town and headed back to Pennsylvania, he said.

The origin of the crack remained vague Tuesday, including whether it predates the earthquake. Some in Sparta say it’s not a crack, but a rut where cows tread on a regular basis on a family farm. Still, investigators are curious.

Mitchell Withers of the Center for Earthquake Research and Information in Memphis, Tennessee, says Simpson-Hunt’s photo raises questions about the type of earthquake that hit Sparta. Was the ground being compressed or stretched?

“It’s difficult to know whether any individual features like the (crack) are a direct result of the earthquake or a secondary effect, such as a ground slump caused by the shaking,” Withers told McClatchy News.

“So long as we don’t get any larger events, I wouldn’t expect those cracks to be a concern. They are a sign that there was enough instability to create them in the first place, so probably not the best place to build a house,” he said.

The gash is definitely not an actual fault line crack, the U.S. Geological Survey says. “Faults do not open up during an earthquake,” reports.

Gaping cracks forming in quakes and swallowing things up are among the biggest myths associated with earthquakes, according to a report by the University of San Diego.

“Certainly, earthquakes can cause cracks to form in the Earth,” the university reported. “However, these cracks are generally quite small and only rarely do they exceed a meter or two in width. And certainly these cracks don’t again close up and swallow somebody whole.”

The U.S. Geological Survey says the 5.1 earthquake originated at a depth of 2.3 miles, and was the strongest of at least seven quakes that rattled the area over 24 hours. Withers says damage was more wide spread in the community than expected, because it was a relatively “shallow” earthquake.

More than 100,000 people reported feeling the earthquake, the USGS reported Monday.