Fracking: Seismic dangers

The central United States has undergone a dramatic increase in seismicity over the past 6 years, rising from an average of 24 events of magnitude ≥ 3.0 earthquakes per year in the years 1973–2008 to an average of 193 events of magnitude ≥ 3.o earthquakes in 2009–2014, with 688 occurring in 2014 alone.” – Justin L. Ruinstein and Alireza Babaie Mahani (Myths and Facts on Waste Water Injection, Hydraulic Fracturing, Enhanced Oil Recovery, and Induced Seismicity.)

That’s craziness.

OK, we’re in CA, land of earthquakes, one of the things that fracking is supposed to increase. However, this is all the BLM says on the subject…

(from the 2014 ROD) (pg. XVIII) “Well stimulation technologies, as currently practiced in California, do not result in a significant increase in seismic hazard. The pressure increases from hydraulic fracturing are too small and too short in duration to be able to produce a felt, let alone damaging, earthquake. In California, only one minor, anomalous earthquake (which occurred in 1991) has been linked to hydraulic fracturing to date. In contrast, disposal of water produced from oil and gas operations into deep injection wells has caused felt seismic events in several states. Expanded oil production for any reason, including expanded use of hydraulic fracturing, would lead to increased volumes of produced water, which, if injected underground could increase seismic hazards.

(from the 2019 EIS) 3.10.1 Seismicity

Approximately 158,500 acres are considered to have high potential for oil and gas occurrence in the Planning Area. The largest area of high oil and gas potential is the San Joaquin Valley, as illustrated in Map 3-14.1 in the 2012 Final EIS. Moderate to high potential for fluid minerals exists outside the San Joaquin Valley region throughout the Coast Range; however, the southern Sierra Nevada are considered to have little to no potential for oil and gas.

A large number of magnitude 2.5 (Richter scale) and greater earthquakes have been recorded in California (CCST 2016). The locations and magnitudes of earthquakes that have occurred in the supplemental hydraulic fracturing analysis areas are shown on Figure 3.10.1.

What we say…

OK, from the section on air pollution, we believe that the BLM is completely underestimating the number of fracked wells that might occur, from the 25% they predict to the 50-60% that Halliburton is doing now. And that’s just talking about wells on newly leased land, not counting new wells on already leased properties.

Based on the EIS statement: (page 2) “… The RFDS projected the exploration, drilling, and production activity that would likely occur in the next 10 years, the anticipated life of the 2014 RMP. This was predicted to be approximately 100 to 400 federal wells to be drilled on federal mineral estate per year during the life of the 2014 RMP. This includes 90 to 360 wells per year on existing leases issued and 10 to 40 wells per year on new leases issued subsequent to the 2014 RMP approval date. Some of these wells were expected to be hydraulically fractured.” THE BLM HAS NO IDEA HOW MANY WELLS WILL EVENTUALLY BE FRACKED, THE UPPER LIMIT ON ALL WELLS OR HOW MUCH “PRODUCED” WASTE WATER WILL BE INJECTED UNDERGROUND.

There is no mechanism discussed to study this issue. There is no upper “STOP” point. Some guy in a BLM is just going to keep stamping permits until CA explodes.


  • Fracking is generally NOT the main cause of induced earthquakes. The deep disposal of wastewater and “produced water” related to gas and oil production is the main culprit behind the causation of frack-quakes in areas like Oklahoma, that used to be essentially quake-free. Technically, all hydraulic fracturing induces earthquakes by intentionally cracking rock, although typically the result is undetectable microearthquakes. 
  • Wastewater is produced at all wells, not just fracking sites.
  • The majority of waste water is “produced water” that comes up with the oil during the extraction process. Hydraulic fracturing chemicals and particles can be as little as 10% of the fluid needing disposal.
  • Produced water is the salty brine from ancient oceans that was entrapped in the rocks when the sediments were deposited. This water is trapped in the same pore space as oil and gas, and as oil and gas is extracted, the produced water is extracted with it. Produced water often must be disposed in injection wells because it is frequently laden with dissolved salts, minerals, and occasionally other materials that make it unsuitable for other uses.
  • Salt water is produced at virtually all oil wells, whether the wells were hydraulically fractured or not.
  • Not all wastewater injection wells induce earthquakes. It depends on volume and rate, the location of faults and the presence of pathways to get to the faults from the well area. Not all areas that drill for oil have all the requirements for earthquakes. HOWEVER, WE DO!
  • Induced earthquakes can occur at 10 miles or more from injection wells and at greater depths than the orginal injection point.
  • Added pressure on the water is not necessary, just pouring it (gravity feed) in will do.
  • Although seismicity associated with salt-water disposal has caused damaging earthquakes, there has not yet been a catastrophic event or fatalities. Preliminary results in a number of areas of induced seismicity indicate that the earthquake hazard in these areas is comparable to the hazard in areas more traditionally known for earthquakes, such as California.
  • In cases when injection of water induces earthquakes of larger magnitudes, the earthquakes are most likely the result of reactivation of nearby pre-existing faults by upsetting the subsurface pressure regimes that keep the fault closed.

Now, about California...

In the 1970’s, research by Dr. Kerry Sieh showed that over the last 15,000 years, great earthquakes (Magnitude “M”>8) on the southern portion of the San Andreas fault occurred in a regular manner, easily dated to within about ±5 years. The time period varied in a regular and reproducible way. The last great earthquake occurred in 1857, and the work showed that the next “Big One” should have been in 1947.

However, beginning at about 1900, extensive drilling for oil occurred in the Los Angeles Basin and surroundings. simultaneously with a rapidly growing population extracting increasingly larger amounts of groundwater. Between both these factors, the balance of oil and water completely changed the subsurface dynamics of the San Andreas fault system, changing the previously reliable but terrifying frequency of catastrophic earthquakes. Now no one knows when the next “Big One” will occur. Or how big it will be, considering that we have locked it up tighter than it ever was.

Recent research has linked earthquakes to wastewater injection. A 2016 study linked wastewater injection in the Tejon oilfield near Bakersfield with a 2005 swarm of two earthquakes reaching magnitude 4.7. These earthquakes occurred about five miles from the injection wells linked to the seismic activity. In a related 2015 study, researchers identified at least three other cases in Kern County where wastewater injection likely induced earthquakes, including earthquakes greater than magnitude 4.1. The seismologists cautioned: “considering the numerous active faults in California, the seismogenic consequences of even a few induced cases can be devastating.

Meanwhile, the industry is trying new, more invasive techniques. Directional drilling, for example, has greatly expanded access to rock formations. Companies also employ high fluid volumes to fill horizontal “well bores” that sometimes extend for miles. And oil and gas producers are using new chemical concoctions collectively called “slick water” that allow injection fluid to flow rapidly enough to generate the high pressure needed to break apart rock. Acidization, another dangerously extreme fossil fuel extraction technique, is similar to fracking but employs hydrofluoric or hydrochloric acid to dissolve rock.

We are only just beginning to understand what we are doing to our local geologies, and this is dangerous. Geologists have been observing the startling increases in earthquakes.  a steady background rate of 21 earthquakes of 3.0 Mw or greater in the central United States per year. Some have suggested that there is hope for mitigating the likelihood of damaging earthquakes through detailed seismic monitoring, careful selection of injection locations, variation of injection rates and pressures in response to ongoing seismicity, and a clear management plan. New research on seismology in places such as Texas and Oklahoma suggests risky and unknown changes. It is just not smart policy to go headlong first – at massive scale – and only later discover the consequences.

Now, back to the BLM...

They actually only provided two maps on seismicity (attached below), the top on locating different kinds of wells, and how productive the area is. The bottom one shows the location and magnitude of earthquakes. NO MAP ON SEISMIC FAULTS, or how the clusters of oil production tracks with earthquakes.

Are you kidding? BLM, what are you doing with your time?


area of fracking

seismic map

Here’s a fault activity map of California centered near Kern County. (This is from the CA Dep. of Conservation, in case the BLM needs one.) Line up Bakersfield between this map and the BLM one above so you can see where you are. The dark red line slanting across the map is the San Andreas Fault.

fault map CA