Map of Kansas oil and gas wells, superimposed upon a geological map of the region, with the epicenter of the earthquake marked.
Kansas had an earthquake yesterday on a Richter scale of 4.8. Like many earthquakes in areas that are mostly sedimentary rock, fracking is suspected. However, the state is firmly in denial about the cause of these mysterious earthquakes.
Studies have shown earthquakes can be caused when fluid, which is byproduct of various methods of oil and gas production, is injected into disposal wells. But a panel commissioned by Kansas Gov. Sam Brownback found there wasn't enough evidence to link the Kansas quakes to oil and gas exploration.
Out of curiosity, I went and looked to see what kinds of geological structures are in the area that experienced the earthquake. Just like in Florida and Texas, these earthquakes are happening around geological areas that have a mix of different strata. The earthquake epicenter is not on a fault line, but instead smack-dab in the middle of several different geological
regions. Namely the Wellington-McPherson lowlands, the Arkansas river lowlands, and the Red Hills. And just like Florida, the earthquakes are happening near an area that already has a history of sinkholes.
Sinkholes are common features of the Red Hills region. These sinkholes were probably formed by the solution of salt and gypsum beds several hundred feet below the surface. The land above then collasped into the empty space, leaving a dip or sinkhole at the surface. Big Basin and Little Basin are two well-known sinkholes in western Clark County.
Another thing I noticed is that oil and gas wells rarely match up neatly and precisely with the location of an earthquake, but the epicenter of this earthquake is nearly equidistant between several large
oil and gas fields. In this case, the Spivey-Grabs-Basil, the Burrton, the Pierce/Koogler/Chesney complex, and the Lost Springs drilling site.
No real surprise that Brownback and his oil, gas and coal cronies are burying their heads in sinkholes instead of admitting the truth - that they'd rather destroy Kansas in the name of short term profit. Ironically, Kansas has always had a bad reputation for extracting mineral reserves without oversight or concern for its residents.
The remains of a long-abandoned coal mine are below the surface of the Cherokee County field Schultz farms for the landowner. The mine's ceilings have been collapsing for years. The front end of a tractor his late father, Robert Schultz, was driving once dropped into a sinkhole. Luckily the big tires on the back of the tractor were wider than the hole, and the disc it was pulling helped stabilize the machine.
UPDATE: I see a lot of you are commenting that there are earthquakes not caused by fracking in sedimentary basins. These sedimentary basins all seem to be in California. As I recall, Lex Luthor's big plan was to have the San Andreas fault break off a bit of California and make all his land waterfront property. So there's natural fault lines in California. Ring of Fire, anybody?
Two things to keep in mind - Texas, Oklahoma, and Kansas are all areas where there's a lot of sedimentary rock, and very little in the way of natural fault lines through plate movement. The Arbuckle Fold extends north from Texas through Oklahoma and into Kansas, and it's the result of plate movement from the west shoving those sedimentary layers.
The other thing to remember is that we never have earthquakes here, or at least we didn't before fracking moved to town. Just off the top of my head, the last recorded earthquake in Texas was in 1995 near Marathon, which is outside Big Bend National Park - an area that geologically has had a lot of volcanic activity because of plate movement.
LAST UPDATE: Many of the commenters noted that injection of wastewater is causing the increased earthquakes. US geophysicist William Elmsworth has conclusively proven that the injection of fluids into deep wells is causing 'induced seismicity.'
Wastewater injection increases the underground pore pressure, which may, in effect, lubricate nearby faults thereby weakening them. If the pore pressure increases enough, the weakened fault will slip, releasing stored tectonic stress in the form of an earthquake. Even faults that have not moved in millions of years can be made to slip and cause an earthquake if conditions underground are appropriate.
Very few of these wastewater disposal sites actually produce earthquakes, but the link is indisputable. We don't know enough about existing fault lines and underground formations to make intelligent decisions about where we should inject wastewater.
I have to wonder if we'd be better off treating and cleaning the water, instead of throwing it away. We're already having a water shortage.