The Wabash Valley seismic zone (also known as the Wabash Valley fault system or fault zone) is a tectonic region located in the Midwestern United States, centered on the valley of the lower Wabash River, along the state line between southeastern Illinois and southwestern Indiana.
The Wabash Valley seismic zone consists largely of vertically oriented ("normal") faults deeply buried under layers of sediment. Although the tectonics of the region are not fully understood and are the subject of ongoing research, these faults are thought by some to be associated with a branch of the New Madrid aulacogen, an old rift zone where the lithosphere actively began to pull apart at perhaps two separate times in the distant past.
Present-day GPS measurements show that the region deforms at about 1–2 mm per year with compression along the Wabash Valley fault zone and extension in southwestern Indiana. [1] [2] [3] The crust in the area has been weakened by the numerous faults, which remain active sites for continuing seismic activity as the motion of the North American plate exerts both compressional and tensional forces.
This zone has been proven to have had earthquakes for the last 20,000 years, with geologic evidence that they may have been as strong as 7.0–7.5 or greater on the Richter scale. [4]
According to the United States Geological Survey, lesser earthquakes occur relatively frequently, but those at a magnitude less than 3.5 or so are usually not felt. Ones strong enough to be felt usually happen once or twice per year, and those large enough to cause moderate damage have occurred every decade or so. Quakes in this region can be felt in a much wider range than those in other zones such as California. [5]
The concern of seismologists Douglas Wiens and Michael E. Wysession of Washington University in St. Louis is that the New Madrid Fault may be becoming less active, while activity on the Wabash Fault could be increasing. Wiens states: "I think everyone's interested in the Wabash Valley Fault because a lot of the attention has been on the New Madrid Fault, but the Wabash Valley Fault could be the more dangerous one, at least for St. Louis and Illinois." "The strongest earthquakes in the last few years have come from the Wabash Valley Fault, which needs more investigation." [4] Numerical modeling indicates that stress transfer following the 1811–1812 New Madrid earthquakes may be loading faults in the Wabash Zone. [6]
Notable modern earthquakes in this zone include:
Epicenter was 3 km west of Bloomingdale, Parke County, Indiana, and was felt as far away as Peoria, Illinois and northern Indiana. [10] No damage was reported. [11]
An intraplate earthquake is an earthquake that occurs in the interior of a tectonic plate, in contrast to an interplate earthquake on the boundary of a tectonic plate. It is also called an intraslab earthquake, especially when occurring in a microplate.
The 1811–1812 New Madrid earthquakes were a series of intense intraplate earthquakes beginning with an initial earthquake of moment magnitude 7.2–8.2 on December 16, 1811, followed by a moment magnitude 7.4 aftershock on the same day. Two additional earthquakes of similar magnitude followed in January and February 1812. They remain the most powerful earthquakes to hit the contiguous United States east of the Rocky Mountains in recorded history. The earthquakes, as well as the seismic zone of their occurrence, were named for the Mississippi River town of New Madrid, then part of the Louisiana Territory and now within the U.S. state of Missouri.
The New Madrid seismic zone (NMSZ), sometimes called the New Madrid fault line, is a major seismic zone and a prolific source of intraplate earthquakes in the Southern and Midwestern United States, stretching to the southwest from New Madrid, Missouri.
The Fukuoka earthquake, also known as the Fukuoka Prefecture West Sea Earthquake, struck Fukuoka Prefecture, Japan at 10:53 am JST on March 20, 2005, off the northwest coast of Fukuoka Prefecture, and lasted for approximately 1 minute. The Japan Meteorological Agency (JMA) measured it as peaking at a magnitude of 7.0 and a maximum seismic intensity of less than six, whereas the United States Geological Survey (USGS) reported a magnitude of 6.6. The quake occurred along a previously unknown fault in the Genkai Sea, North of Fukuoka city, and the residents of Genkai Island were forced to evacuate as houses collapsed and multiple landslides occurred in various places. Investigations subsequent to the earthquake determined that the new fault was most likely an extension of the known Kego fault that runs through the centre of the city.
The Wabash Valley is a region located in sections of both Illinois and Indiana. It is named for the Wabash River and, as the name is typically used, spans the middle to the middle-lower portion of the river's valley and is centered at Terre Haute, Indiana. The term Wabash Valley is frequently used in local media in Clinton, Lafayette, Mount Carmel, Princeton, Terre Haute, and Vincennes all of which are either on or near the Lower Wabash River.
The 1950 Assam–Tibet earthquake, also known as the Assam earthquake, occurred on 15 August and had a moment magnitude of 8.7. The epicentre was located in the Mishmi Hills. It is one of the strongest earthquake ever recorded on land.
The 2008 Illinois earthquake was one of the largest earthquakes ever recorded in the Midwest state of Illinois. This moderate strike-slip shock measured 5.2 on the moment magnitude scale and had a maximum Mercalli intensity of VII (Very strong). It occurred at 04:36:59 local time on April 18 near Bellmont and Mount Carmel, Illinois, within the Wabash Valley seismic zone. Earthquakes in this part of the country are often felt at great distances.
The 1998 Pymatuning earthquake occurred in the U.S. state of Pennsylvania on September 25 at 19:52 UTC. With a magnitude of 5.2 mbLg, it was the largest recorded earthquake in Pennsylvania's history.
In the early morning hours of August 16, 1931, a powerful earthquake occurred in West Texas with a maximum Mercalli intensity of VIII (Severe). Estimates of its magnitude range between 5.8 and 6.4 mb, making it the most powerful earthquake ever recorded in Texas history. Its epicenter was near the town of Valentine, Texas; there, the earthquake caused damage to many homes and buildings. The earthquake may have been caused by movement along oblique-slip faulting in West Texas, the most seismically active region in the state. Shaking from the earthquake was perceptible within a 400 mi (640 km) radius of the epicenter, affecting four U.S. states and northern Mexico. Several foreshocks and aftershocks accompanied the primary temblor, with the aftershocks continuing until at least November 3, 1931. The main earthquake caused no fatalities, though several people sustained minor injuries; the damage in Valentine amounted to $50,000–$75,000.
The 1968 Illinois earthquake was the largest recorded earthquake in the U.S. Midwestern state of Illinois. Striking at 11:02 a.m. on November 9, it measured 5.3 on the Richter scale. Although no fatalities occurred, the event caused considerable structural damage to buildings, including the toppling of chimneys and shaking in Chicago, the region's largest city. The earthquake was one of the most widely felt in U.S. history, largely affecting 23 states over an area of 580,000 sq mi (1,500,000 km2). In studying its cause, scientists discovered the Cottage Grove Fault in the Southern Illinois Basin.
The 1986 Chalfant Valley earthquake struck southern Mono County near Bishop and Chalfant, California at 07:42:28 Pacific Daylight Time on July 21. With a moment magnitude of 6.2 and a maximum Mercalli intensity of VI (Strong), the shock injured two people and caused property damage estimated at $2.7 million in the affected areas. There was a significant foreshock and aftershock sequence that included a few moderate events, and was the last in a series of three earthquakes that affected southern California and the northern Owens Valley in July 1986.
The 2010 Baja California earthquake occurred on April 4 with a moment magnitude of 7.2 and a maximum Mercalli intensity of VII. The shock originated at 15:40:41 local time south of Guadalupe Victoria, Baja California, Mexico.
The 1916 Irondale earthquake struck in the north-central region of the U.S. state of Alabama on October 18. The strongest earthquake in state history, it registered an estimated Richter scale magnitude of 5.1 and resulted in minor damage. Damage was limited to Shelby and Jefferson counties and reached its maximum severity near the epicenter in the city of Irondale, including cracked windows, fallen chimneys, and dried-up wells. While there were no fatalities, the earthquake spawned widespread panic, prompting alarmed workers to evacuate tall buildings.
On August 23, 2011, a magnitude 5.8 earthquake hit the Piedmont region of the U.S. state of Virginia at 1:51:04 p.m. EDT. The epicenter, in Louisa County, was 38 mi (61 km) northwest of Richmond and 5 mi (8 km) south-southwest of the town of Mineral. It was an intraplate earthquake with a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale. Several aftershocks, ranging up to 4.5 Mw in magnitude, occurred after the main tremor.
The 2011 Oklahoma earthquake was a 5.7 magnitude intraplate earthquake which occurred near Prague, Oklahoma on November 5 at 10:53 p.m. CDT in the U.S. state of Oklahoma. The epicenter of the earthquake was in the vicinity of several active wastewater injection wells. According to the United States Geological Survey (USGS), it was the most powerful earthquake ever recorded in Oklahoma until the 2016 Oklahoma earthquake. The previous record was a 5.5 magnitude earthquake that struck near the town of El Reno in 1952. The quake's epicenter was approximately 44 miles (71 km) east-northeast of Oklahoma City, near the town of Sparks and was felt in the neighboring states of Texas, Arkansas, Kansas and Missouri and even as far away as Tennessee and Wisconsin. The quake followed several minor quakes earlier in the day, including a 4.7 magnitude foreshock. The quake had a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale in the area closest to the epicenter. Numerous aftershocks were detected after the main quake, with a few registering at 4.0 magnitude.
The 2019 Ridgecrest earthquakes of July 4 and 5 occurred north and northeast of the town of Ridgecrest, California located in Kern County and west of Searles Valley. They included three initial main shocks of Mw magnitudes 6.4, 5.4, and 7.1, and many perceptible aftershocks, mainly within the area of the Naval Air Weapons Station China Lake. Eleven months later, a Mw 5.5 aftershock took place to the east of Ridgecrest. The first main shock occurred on Thursday, July 4 at 10:33 a.m. PDT, approximately 18 km (11.2 mi) ENE of Ridgecrest, and 13 km (8.1 mi) WSW of Trona, on a previously unnoticed NE-SW trending fault where it intersects the NW-SE trending Little Lake Fault Zone. This quake was preceded by several smaller earthquakes, and was followed by more than 1,400 detected aftershocks. The M 5.4 and M 7.1 quakes struck on Friday, July 5 at 4:08 a.m. and 8:19 p.m. PDT approximately 10 km (6 miles) to the northwest. The latter, now considered the mainshock, was the most powerful earthquake to occur in the state in 20 years. Subsequent aftershocks extended approximately 50 km (~30 miles) along the Little Lake Fault Zone.
The 1995 Menglian earthquake or 1995 Myanmar–China earthquake occurred on 12 July at 05:46:43 local time in the Myanmar–China border region. The earthquake had an epicenter on the Myanmar side of the border, located in the mountainous region of Shan State. It registered 7.3 on the Chinese surface-wave magnitude scale (Ms ) and 6.8 on the moment magnitude scale (Mw ). With a maximum Mercalli intensity assigned at VIII, it killed 11 people and left another 136 injured. Over 100,000 homes in both countries were destroyed and 42,000 seriously damaged. Some damage to structures were also reported in Chiang Mai and Chiang Rai, Thailand. The low death toll from this earthquake was attributed to an early warning issued prior to it happening. Precursor events including foreshocks and some seismic anomalies led to an evacuation of the area before the mainshock struck. It is thought to be one of the few successfully predicted earthquakes in history.
An earthquake occurred off the coast of the Alaska Peninsula on July 28, 2021, at 10:15 p.m. local time. The large megathrust earthquake had a moment magnitude of 8.2 according to the United States Geological Survey (USGS). A tsunami warning was issued by the National Oceanic and Atmospheric Administration (NOAA) but later cancelled. The mainshock was followed by a number of aftershocks, including three that were of magnitude 5.9, 6.1 and 6.9 respectively.
The 1895 Charleston earthquake, also known as the Halloween earthquake, occurred on October 31, at 05:07 CST near Charleston, Missouri. It had an estimated moment magnitude of 5.8–6.6 and evaluated Modified Mercalli intensity of VIII (Severe). The earthquake caused substantial property damage in the states of Missouri, Illinois, Ohio, Alabama, Iowa, Kentucky, Indiana, and Tennessee. Shaking was widespread, being felt across 23 states and even in Canada. At least two people died and seven were injured.
The 1992 Joshua Tree earthquake occurred at 9:50:25 p.m. PDT on April 22 in Southern California. The magnitude 6.2 earthquake struck under the Little San Bernardino Mountains, near the town of Joshua Tree, California. Though no deaths were reported, the earthquake caused 32 injuries. A maximum Mercalli intensity of VII was observed in Joshua Tree and caused light to moderate damage. The event preceded the Landers and Big Bear earthquakes by two months but is now recognized as the beginning of a series of major earthquakes that culminated in two events on June 28, 1992.