RENO COUNTY, Kan. — Earthquakes keep rocking Kansas this year. It might have some people a little on edge about whether the state can expect a large-scale earthquake. The good news: It’s pretty unlikely for Kansas to see a quake like the ones that rattle California. There isn’t an active enough fault-line to produce the more damage-heavy tremors.
An investigation is underway to find out why the state has received so many quakes and what can be done to prevent them. At least 50 quakes have shaken up an array of counties in the Sunflower State this year. A series of three quakes rattled portions of south-central Kansas on Sunday and Monday.
Every 24 hours, more than 1,000 earthquakes occur all around the planet. In simple terms, earthquakes occur when rocks beneath the earth’s surface move suddenly along the faults. The faults are fractures in weak points in the earth. The movement impacts pressure – energy builds up and needs to go somewhere, which gets released in tremors. The strength of an earthquake depends on the amount of stress it released.
The Kansas Geological Survey said the strongest quake measured Monday was a 3.8 tremor. It was reported around 2:30 a.m. in Chase County about 75 miles northeast of Wichita. Another quake rattled off around 10 a.m. It was a 3.6 magnitude quake. A quake was also reported in Reno County Sunday at 10:20 a.m. Hutchinson is in Reno County, the area is about 50 miles northwest of Wichita.
Property damage doesn’t usually occur until a quake hits 4.0 on the Richter magnitude scale. A spike in quakes goes all the way back to 2014. Researchers blame many of the quakes on wastewater injection wells from oil and gas production.
Kansas, for the most part, is classified as a minor damage zone, although a zone of moderate damage runs across the state from Nebraska to Oklahoma. Seismic risk is measured to help architects and engineers with landscaping and is used with building codes.
After oil prices dropped and more regulations were added, the number of quakes decreased in 2015. This year is a different story. The back-to-back quakes in Reno County have led the Kansas Corporation Commission to look further into injection well activity. The regulatory agency took that action after a cluster of 17 earthquakes hit in Reno County over five days from August 15 to August 20.
The strongest quake of the year was a 4.8 magnitude tremor on June 22.
“Amid damage reports and a concern for public safety, the KCC is conducting an investigation and will evaluate whether additional action is needed to safeguard Kansans,” KCC spokesperson Linda Berry said in a written statement announcing the investigation.
Investigators are collecting data and analyzing recent oilfield injection well activity in a 15-miles radius of where the earthquakes took place.
Investigators will focus on the Arbuckle Formation, which has had issues with quakes before this year. Southern Kansas quakes overlap with an increase in fracking, an oil industry term for using high-pressure liquid to fracture subsurface rock to free trapped pockets of oil and gas. Injection peaked in 2015 at almost 16 million barrels. Since then, it’s fluctuated in the 14.5 to 14.8 million barrel range.
Reno County wasn’t part of a study that led to KCC-ordered limits on wastewater disposal in 2015 and 2016. That action has been credited with calming seismic activity in Barber, Harper, Kingman, Sedgwick and Sumner counties.
Historic Quake from the 1800s in Manhattan, Kansas
The largest earthquake in the state dates back more than 100 years. The 1867 Manhattan earthquake struck Riley County, Kansas in the United States on April 24, 1867. It measured 5.1 on a seismic scale. Its epicenter was near the town of Manhattan, which now has a population of more than 53,000 people.
Manhattan is near the Nemaha Ridge, a long anticline structure that is riddled with faults. The nearby Humboldt Fault Zone is an area of concern for quakes, but engineers and scientists haven’t raised an alarm for any impending danger.
The historic earthquake caused minor damage to parts of Kansas, Iowa and Missouri. It was felt over an area of 200,000 square miles. Some people claimed they felt the quake in Indiana, Illinois, and Ohio, though investigators question the authenticity of the reports from Ohio.
The 1867 Manhattan Earthquake fractured walls, downed chimneys, and caused widespread panic. The quake loosened stones and changed river water flow. Within the epicenter of the quake, clocks stopped, people felt movement inside their properties, and livestock was noticeably spooked. The following day an aftershock went off between 3 a.m. and 4 a.m.
At a farm 3 miles south of the city of Wamego, the earthquake caused liquefaction of the ground — this can lead to foundation troubles. In Louisville, the quake knocked over horses and chimneys crumbled.
In Paola, the earthquake destroyed one wall of a large Republican newspaper office building. Waves on the Kansas River reached 2.0 feet in height. The city of Atchison felt two shocks – lamps and bottles fell at a drug store, and water flow in rivers and creeks turned erratic. No buildings sustained damage, but people ran into the streets panicked and confused.
In Kansas City, tables moved, walls cracked, water spilled from glasses, and plaster cracked. The city of Lawrence felt three earthquakes within 30 seconds. The tremors knocked stones off a local church, it rattled silverware and glass, and flipped over a stove in one home.
A series of articles published by the Chicago Tribune described the extent of the damage in the article “At Kansas City.” The article noted the earthquake shook homes with a sudden burst, giving off a resonating roar like sound. The Tribune observed in its article that in “Leavenworth, Kansas the earthquake was completely unexpected, describing the event as sudden in its coming and departure.”
The article for readers in the present makes it clear that earthquakes were not common in Kansas in the 1800s, and people who witnessed the 1867 one were pretty disturbed by it.
In the present, Kansas is not poised for a significant threat from quakes. Again, the most active spot is the Nemaha Ridge. The Humboldt Fault Zone, just off the Ridge, lies just 12 miles east of the Tuttle Creek Reservoir near Manhattan. The worst case scenario that the United States Army Corps of Engineers have predicted is that an earthquake there would likely destroy the dam, releasing 91,440 m of water per second. This would flood the nearby area, threatening roughly 13,000 people and 5,900 homes.
The United States Army Corps of Engineers concluded that a moderate quake between 5.7 and 6.6 would cause sand underneath the dam to liquefy into quicksand. The dam would then spread out and drop up to three feet. Earthquakes that pose any kind of threat to the dam occur on a cycle of roughly 1,800 years. To counter any threat, the Corps of Engineers has worked to strengthen the dam and come up with plans to mitigate any possible disaster.
More than 500 earthquakes have rocked Kansas since 2013, and this has contributed to the reactivation of ancient fault lines. In 2016, the United States Geological Survey made hazard maps for the state; back then the report found there was only a 1% or lower risk of a major earthquake for the next year.