Clintonville officials say an earthquake detected by the US Geological Survey is the source of mysterious rumblings this week. The biggest quake measured a relatively small 1.5 on the Richter scale, at 12:15 Tuesday morning, leaving some residents skeptical the quake is the cause of the thunderous booms.
Geological Survey physicist Paul Caruso said he’d be skeptical that loud, repeated sounds could be tied to such small earthquakes but he agreed it’s possible.
City administrator Lisa Kuss admitted an earthquake of that magnitude would not be felt in many other places, but the type of rock that Wisconsin has transmits seismic activity very well. She said the granite formations could also explain the loud booms that kept waking up residents.
A geophysicist at the National Earthquake Information Center in Golden, Colorado said the depth of the quake could be a contributing factor. “It’s actually quite rare that they’re felt,” John Bellini said. “But because they’re felt, it means they are probably pretty close to the surface.”
Clifford Thurber, a UW-Madison geophysics professor, said there needs to be more conclusive studies and evidence before a conclusion can be nailed down. He said if the seismic activity is one-or-two miles deep, it could be a quake, but if it’s only 100-feet deep, it could be something else. Thurber said Clintonville might have the types of small earthquakes that Moodus, Connecticut has felt for centuries. But it’s more likely that an answer will never be found.
Mike Kemmeter-WHBY contributed to this report