Earthquakes said to have caused the booms and shaking ground in ClintonvilleWisconsin News
The biggest quake measured a relatively small 1.5 on the Richter scale around 12:15 a.m. Tuesday, according to the U.S. Geological Survey.
City Administrator Lisa Kuss says “the mystery is solved” in Clintonville.
The U.S. Geological Survey reported Thursday afternoon that a “swarm” of small earthquakes are what caused the ground to shake numerous times this week.
About 250 people attended a hastily-called public meeting at Clintonville High School Thursday night to learn more.
Kuss said it was a fluke that a portable seismic detector just happened to be traveling in the area. It picked up the activity along with Geological Survey monitors as far away as Linden, Iowa.
The biggest quake measured a relatively small 1.5 on the Richter scale around 12:15 a.m. Tuesday.
Kuss said 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 late Sunday, Monday and Tuesday nights and into the following mornings.
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. He said a half-dozen seismic monitors picked up the activity.
UW profess says more study needed
UW-Madison geo-physics professor Clifford Thurber says 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 says Clintonville might have the types of small earthquakes that Moodus, Conn., has felt for centuries.
Kuss told residents it could be a one-time-only event. She said there’s nothing that says if it happened once it’s likely to happen again.