A rare Northwoods earthquake becomes important lesson for Wisconsinites

CRANDON, Wis. (WSAW) - When we think of America’s Dairyland, earthquakes aren’t usually on the list of common weather occurrences. Especially in northern Wisconsin.

“There’s a theory that lake-level fluctuations can actually stress the crust a little bit,” Seismologist with the U.S. Geological Survey Susan Hough said. “This one is well away from the Great Lakes. There is not an obvious thing you can point to that would’ve caused an earthquake there.”

The earthquake measured at 2.5 on the Richter Scale — the lowest rating that is strong enough to register on the scale. Hough said because Crandon is a remote part of Wisconsin, more people felt the impact compared to higher-populated areas.

“In California, you wouldn’t even likely feel an earthquake that small,” she said. “It’s on the ragged edge of generating shaking that’s strong enough to be felt.”

The earthquake went 10 kilometers, just over six miles, underground, but Hough considers that a good problem to have.

“If it’s deep, the energy has a chance to spread out like ripples in a pond,” Hough explained. “And so that keeps the jolts from being too strong on the surface where people live.”

If you encounter an earthquake in the future, Hough said to drop to the ground, cover if you’re able to under a table or desk, and hold on until the shaking stops.

“We recommend people do that immediately,” she said. “If you sit around and wait to see if the shaking’s gonna get really strong, it may be too late to take protective action.”

Hough said it’s never impossible for more earthquakes to occur in the area. However, the odds of something bigger happening in the coming days are low. She also doesn’t expect an active sequence of earthquakes here in Wisconsin.

For more information and what to do during an earthquake or on earthquakes anywhere in the world, click here.