 1947 Wisconsin earthquake approximate tremor area.[AI-generated?] The dot shows the location of Milwaukee. | |
| UTC time | 1947-05-06 20:25 |
|---|---|
| ISC event | n/a |
| USGS-ANSS | n/a |
| Local date | May 6, 1947 |
| Local time | 15:27 (CST) [1] |
| Magnitude | 4.2[2] |
| Epicenter | 43°03′N 87°57′W / 43.05°N 87.95°W |
| Max. intensity | MMI V (Moderate)[3] |
The 1947 Wisconsin earthquake took place on May 6, immediately south of Milwaukee at 15:27 (CST). It was the largest tremor to be historically documented in Wisconsin, but was not recorded by seismographs.
History
[edit]The area had been previously shaken by the 1909 Wabash River earthquake, causing damage assessed at VII (Very strong) on the Modified Mercalli scale across the Wisconsin-Illinois border. Two earthquakes were also reported in the state in 1912. Shocks in 1919 and 1925, the first from Missouri and the latter from Canada, occurred over enormous zones and affected the entire region, though not seriously. Earthquakes struck Wisconsin again in 1937 and 1939.[3]
Earthquake
[edit]For a few seconds at 15:27,[4] the earthquake was felt in a 3,000-square-mile (7,770 km2) strip of land in southeastern Wisconsin, in a 99-mile (159 km) wide area stretching across the Wisconsin-Illinois border, and to Lake Michigan and Waukesha.[3]
Damage
[edit]Damage consisted of broken windows and fallen porcelain, pots and dishes.[5] The locals' initial impression was that an explosion had taken place. Many evacuated buildings into the streets.[5] Corporate office buildings were emptied of workers.[6] Numerous calls were made local fire departments, police stations and newspapers. Three reports were made to the Milwaukee Fire Department, all describing explosions.[6]
Often described as "sharp", this was the most powerful earthquake to date in Wisconsin's seismological history. The earthquake broke a seismograph at Marquette University.[6] Many hotels, such as the Schroeder Hotel in Milwaukee, were rocked by the tremor. However, the earthquake caused no serious damage or casualties.[6]
See also
[edit]References
[edit]- ^ Walter, Jennifer (May 6, 2022). "75 years ago, Milwaukee experienced the most severe earthquake in Wisconsin history". Milwaukee Magazine. Retrieved August 19, 2025.
- ^ Dutch, Steve (1999). "Wisconsin Earthquakes". University of Wisconsin - Green Bay. Retrieved August 20, 2025.
- ^ a b c "Wisconsin: Earthquake History". United States Geological Survey. January 30, 2009. Archived from the original on March 26, 2009. Retrieved May 6, 2009.
- ^ Walter, Jennifer (May 6, 2022). "75 years ago, Milwaukee experienced the most severe earthquake in Wisconsin history". Milwaukee Magazine. Retrieved August 19, 2025.
- ^ a b "Today in Earthquake History: May 6". United States Geological Survey. January 30, 2009. Retrieved May 6, 2009.
- ^ a b c d "Sharp Earthquake Rocks Buildings in Milwaukee". Saint Petersburg Times. May 6, 1947. Retrieved May 8, 2009.