Sandwich Fault Zone

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. 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.

See also

• List of earthquakes in Illinois

References

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

Further reading

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