Earthquakes in North Central Kansas

 

Earthquakes in North Central Kansas

 

By Terry Bailey

 


 

According to the experts from the Kansas Geological Survey, the earthquakes in Jewell County are not being caused by fracking or other oil-well drilling activities. They are, instead, simply a naturally occurring phenomenon. It should be hundreds of years before an earthquake any more severe than the 3.0 – 3.3 quakes already experienced in Jewell County should occur. On the other hand, a major 4.0 or 5.0 quake could take place tomorrow. What Mother Nature will do is hard to predict.

 

Ross Mandel and Rick Miller from the Kansas Geological Survey, located on the campus of the University of Kansas, addressed an audience of about 30 interested citizens at the conference center at the NCK Tech College Tuesday morning, September 19th. In attendance also was Representative Susan Concannon and Representative Swanson from Clay Center. Mandel said the mission of the Geological Survey is not well understood. To emphasize the point he said that after a small earthquake had been noticed in South Central Kansas, a lady called their office and asked, “Can you come down here and fix this thing?” He said, “We do the research and analyze the data and then turn it over to the decision makers to act upon.” Additionally the KGS has an outreach program for education purposes.

 

At this point Rick Miller took over the presentation duties and said, “Clearly, the reason we are here is driven by the events in Jewell County since April.”

 

He noted that tremors and quakes have been experienced in Trego, Ellis and Osborne County for a number of years. Generally, when they happen people go about their business with not much notice. However, these events are new in Jewell County and they do create notice and concern.

 

Miller produced two charts. One depicted seismic activity from 1867 to 2012. The other show activity from 2012 to the current time. Miller said the largest documented earthquake to occur in Kansas happened near Wamego in 1867. At the time there were no detection devices so they relied on newspaper accounts and personal narratives to judge the size of the activity. All in all, Kansas has experienced slightly over 9,000 recorded earthquakes.

 

The largest area of seismic activity occurs in Harper, Barber, and Sumner counties in South Central Kansas near the Oklahoma border. In 2012, 17 earthquakes of 2.0 or higher were reported in Kansas with the majority of these taking place in Harper County. An earthquake must be measured at 2.5 to be noticed by most people. The KGS has 24 monitoring stations strategically placed around the state.

 

When drilling for oil, for every barrel of oil captured, 60 to 70 barrels of saltwater is created. Kansas has about 5,000 disposal wells in which the saltwater is returned.

 

How about Jewell County, which has recorded 30 events in 2017 with the largest measuring 3.4.? Miller noted that events previously noticed in Smith County have moved into Jewell County with activity recently noted in Republic County.

 

He said that earth quakes generally occur in clusters, usually around fault areas. Miller said, “We do not know if Jewell County has a geological fault. We have no data to prove it one way or the other. We do know that one earthquake can cause another earthquake.”

 

Miller went on to say, “Most likely there are some natural faults in Jewell County that may be related to the seismic activity. Salt water injection does not appear to be the cause. The closest injection well is in southwest Osborne County. The data does not indicate any catastrophic earthquake activity is expected, but, on the other hand, a 5.0 event could happen tomorrow.”

 

Miller summed up the earthquake experience by telling the audience that soil composition affects the travel of seismic waves. If the surface and subsurface composition is alluvial soil the shock waves are easily transmitted. If the land is compose of rocky ledges, the shock waves do not travel well.