The 2008 Illinois earthquake was one of the largest

earthquakes An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they c ...

ever recorded in the Midwest

state State most commonly refers to: * State (polity), a centralized political organization that regulates law and society within a territory **Sovereign state, a sovereign polity in international law, commonly referred to as a country **Nation state, a ...

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

. This moderate strike-slip shock measured 5.2 on the

moment magnitude scale The moment magnitude scale (MMS; denoted explicitly with or Mwg, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. was defined in a 1979 paper ...

and had a maximum Mercalli intensity of VII ''(Very strong)''. It occurred at on April 18 near Bellmont and

Mount Carmel, Illinois Mount Carmel is a city in and the county seat of Wabash County, Illinois, United States. At the time of the 2020 census, the population was 7,015, and it is the largest city in the county. The next largest town in Wabash County is Allendale, ...

, within the Wabash Valley seismic zone. Earthquakes in this part of the country are often felt at great distances.

Tectonic setting

Situated in a stable continental region of the

Midwestern United States The Midwestern United States (also referred to as the Midwest, the Heartland or the American Midwest) is one of the four census regions defined by the United States Census Bureau. It occupies the northern central part of the United States. It ...

, the Wabash Valley seismic zone (WVSZ) is an area of dispersed seismic activity that encompasses the border areas of Illinois, Indiana, and Kentucky. This broad, multistate zone of intraplate seismicity lay just to the north of the New Madrid seismic zone and comprises both strike-slip and dip-slip earthquake mechanisms across numerous named faults,

graben In geology, a graben () is a depression (geology), depressed block of the Crust (geology), crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German language, German, meaning 'ditch' or 't ...

s, and

anticline In structural geology, an anticline is a type of Fold (geology), fold that is an arch-like shape and has its oldest Bed (geology), beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex curve, c ...

Earthquake

Rapid development and expansion of services from the

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

was taking place in the 2000s in terms of earthquake monitoring and information dissemination services. A number of products from it and its subdivisions that relay information to the public over the Internet were displayed during the event. An automated system from the

National Earthquake Information Center The National Earthquake Information Center (abbreviated NEIC) is part of the United States Geological Survey (USGS) located on the campus of the Colorado School of Mines in Golden, Colorado. The NEIC has three main missions: * First, the NEIC de ...

, for example, sent an initial notification containing magnitude, depth, and location within two and a half minutes of the mainshock.

Felt area

The shock was felt as far west as

Omaha, Nebraska Omaha ( ) is the List of cities in Nebraska, most populous city in the U.S. state of Nebraska. It is located in the Midwestern United States along the Missouri River, about north of the mouth of the Platte River. The nation's List of United S ...

, as far south as

Atlanta, Georgia Atlanta ( ) is the List of capitals in the United States, capital and List of municipalities in Georgia (U.S. state), most populous city in the U.S. state of Georgia (U.S. state), Georgia. It is the county seat, seat of Fulton County, Georg ...

, as far east as

Kitchener, Ontario Kitchener is a city in the Canadian province of Ontario, about west of Toronto. It is one of three cities that make up the Regional Municipality of Waterloo and is the regional Administrative centre, seat. Kitchener was known as Berlin until a ...

, and

West Virginia West Virginia is a mountainous U.S. state, state in the Southern United States, Southern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States.The United States Census Bureau, Census Bureau and the Association of American ...

, and as far north as the

Upper Peninsula of Michigan The Upper Peninsula of Michigan—also known as Upper Michigan or colloquially the U.P. or Yoop—is the northern and more elevated of the two major landmasses that make up the U.S. state of Michigan; it is separated from the Lower Peninsula of ...

. The earthquake was felt so far away, compared to earthquakes in other regions, because the old, rigid bedrock beneath much of the Midwest allows the

seismic wave A seismic wave is a mechanical wave of acoustic energy that travels through the Earth or another planetary body. It can result from an earthquake (or generally, a quake), volcanic eruption, magma movement, a large landslide and a large ma ...

s to propagate further.

Damage

Close to the epicenter in Mount Carmel, Illinois, a woman was briefly unable to exit her home due to a collapsed porch, and a two-story apartment building was evacuated because of loose and falling bricks. The

Edwards County Edwards County is the name of several counties in the United States: *Edwards County, Illinois *Edwards County, Kansas *Edwards County, Texas Edwards County is a county located on the Edwards Plateau in the U.S. state of Texas. As of the ...

sheriff's department took reports of minor damage in West Salem, Illinois. Just across the

Wabash River The Wabash River () is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed May 13, 2011 river that drains most of the state of Indiana, and a significant part of Illinois, in the United ...

in Indiana, Unit 4 at the

Gibson Generating Station The Gibson Generating Station is a coal-burning power plant located at the northernmost end of Montgomery Township, Gibson County, Indiana, United States. It is close to the Wabash River, southeast of Mount Carmel, Illinois, south of the mou ...

automatically shut down due to its vibration sensors, and in

Princeton Princeton University is a private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the Unit ...

, a woman was cut when a crystal figurine was knocked from a shelf in her home. A man had an eye injury at an unknown location, but medical attention was not sought. In

Louisville, Kentucky Louisville is the List of cities in Kentucky, most populous city in the Commonwealth of Kentucky, sixth-most populous city in the Southeastern United States, Southeast, and the list of United States cities by population, 27th-most-populous city ...

, some bricks broke off from an older building near downtown. Slightly further away in

St. Louis, Missouri St. Louis ( , sometimes referred to as St. Louis City, Saint Louis or STL) is an Independent city (United States), independent city in the U.S. state of Missouri. It lies near the confluence of the Mississippi River, Mississippi and the Miss ...

, a portion of the South Kingshighway Boulevard

viaduct A viaduct is a specific type of bridge that consists of a series of arches, piers or columns supporting a long elevated railway or road. Typically a viaduct connects two points of roughly equal elevation, allowing direct overpass across a wide ...

were closed because of loose pieces of concrete, but whether this was debris-related is unknown, and traffic resumed half an hour later. Several chimneys also collapsed in south St. Louis, the St. Francis de Sales Oratory reported damage to its steeple, and the Basilica of St. Louis King of France reported small fragments from the mosaic ceiling. About 35,000 people in St. Louis County were without power because the Labadie Power Station went offline due to excessive vibrations. Power was restored by midmorning.

Indiana Indiana ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Michigan to the northwest, Michigan to the north and northeast, Ohio to the east, the Ohio River and Kentucky to the s ...

, and

Kentucky Kentucky (, ), officially the Commonwealth of Kentucky, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Illinois, Indiana, and Ohio to the north, West Virginia to the ...

state highway crews investigated if any roads or bridges were damaged in the area. Cracks were reported on

U.S. Route 51 U.S. Route 51 or U.S. Highway 51 (US 51) is a major south–north United States highway that extends from the western suburbs of New Orleans, Louisiana, to within of the Wisconsin–Michigan state line. As most of the United States Numbered Hi ...

near

Cairo Cairo ( ; , ) is the Capital city, capital and largest city of Egypt and the Cairo Governorate, being home to more than 10 million people. It is also part of the List of urban agglomerations in Africa, largest urban agglomeration in Africa, L ...

at the state's southern tip. No roads were reported to be damaged in Kentucky, but inspections were being conducted in the Louisville, Paducah, and Henderson districts, according to the Kentucky Department of Transportation.

Aftershocks

More than 250

aftershock In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in Epicenter, the same area of the Mainshock, main shock, caused as the displaced Crust (geology), crust adjusts to the effects of the main shock. Large earthq ...

s ranging in magnitude from 0.7 to 4.6 were documented in the month following the mainshock, including the largest, which occurred later in the morning. The other stand-out shocks in the sequence were the M4 event on April 21, an M4.2 event on April 25, and a M3.4 shock on June 5 CDT.

Response

Many precautionary measures were taken, including several evacuations. All

Vincennes University Vincennes University (VU) is a public college with its main campus in Vincennes, Indiana, United States. Founded in 1801 as Jefferson Academy, VU is the oldest public institution of higher learning in Indiana. VU was chartered in 1806 as the In ...

dormitories were evacuated as a precaution, but no damage was discovered and students were allowed to return after about 45 minutes. A coal mine in

Gibson County, Indiana Gibson County is a county in the southwestern part of the U.S. state of Indiana. As of the 2020 United States census, the population was 33,011. The county seat is Princeton. History In 1787, the fledgling United States defined the Northw ...

, was also evacuated, but miners returned to work shortly afterwards. The Gibson County

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system was briefly knocked offline due to a flood of calls, but after about 15 minutes, service was restored.

References

External links

Seismographic Readings for this specific earthquake
– Illinois State Geological Survey
Seismographic Readings for 15:15 (UTC) aftershock
– Illinois State Geological Survey
Lawrence County E911 Security Camera Video of QuakeApril 18, 2008, Mt. Carmel, Illinois: Magnitude 5.2 Earthquake and Aftershocks
– Illinois State Geological Survey
5.2 earthquake rattles skyscrapers, nerves across Midwest
– Associated Press
An Earthquake Rattles the Midwest
– ''

The New York Times ''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of ...

'' {{DEFAULTSORT:Illinois Earthquake, 2008 2008 earthquakes 2008 natural disasters in the United States Geology of Illinois Southwestern Indiana Earthquakes in the United States Natural disasters in Illinois April 2008 in the United States 2008 in Illinois 2008 in Indiana