Sandwich Fault Zone Explained

The Sandwich Fault Zone is a fault zone that runs northwest from Oswego to Ogle County, transecting Lee County in Northern Illinois. The fault has generally not been active, although a minor earthquake was reported in 2002 and 2010.^[1] On July 15, 2024, at 0253hrs CST a 3.4 magnitude earthquake was recorded with an epicenter roughly 2 km North West of Somonauk, Il. It has a largely 400 to 600-foot vertical displacement, although parts can reach up to an 800-foot displacement, and is likely a configuration of several smaller faults, varying in both direction and displacement.^{[2] [3]}

See also

• List of earthquakes in Illinois

References

• Book: Kolata . Dennis R. . Buschbach . T. C.. Treworgy. Janis D. . 1978 . The Sandwich Fault Zone of Northern Illinois . Information circular / Illinois State Geological Survey ; [no. 505] . Urbana . Illinois State Geological Survey. 10111/UIUCOCA:sandwichfaultzon505kola .

Further reading

• Nuggets of History . Martha, The Ground is Shaking Again: A Chronicle of an Uncommon Rockford Event. Rockford Historical Society . Rockford, Illinois. 48. 3. McMakin. Dean. September 2010.

Notes and References

1. Web site: No injuries, damage in 3.8-magnitude earthquake. February 10, 2010. WLS-TV. 15 March 2010.
2. Web site: When is the next earthquake in Illinois?. Morrow. William. May 2003. Water Resources Update – Illinois District Newsletter. United States Geological Survey. 4–5. https://web.archive.org/web/20171011130306/https://il.water.usgs.gov/hot/spring2003.pdf. 7 March 2010. 2017-10-11.
3. Book: McGarry, Christopher S. . Bedrock Geology of Lee County Illinois. 1999. Illinois State Geological Survey. 4 December 2017. 41366650.