Could yesterday’s earthquake have been caused by fluid injection into hydrofracking wells? The answer I can give you is yes, it is possible, and here is how I know. I experienced numerous man made earthquakes in Colorado in the 1960’s as a result of millions of gallons of fluids being pumped into a 12,000 foot deep well maintained by the Rocky Mountain Arsenal (RMA)

I lived in the Denver suburbs in the 1960’s, in Jefferson county. We lived not too far from the Rocky Mountain Arsenal located in Commerce City, a little bit northeast of Denver. The Arsenal was a chemical weapons facility operated by the Defense Department. In 1961, a deep injection well was drilled to a depth of 12,000 feet.

Now Colorado is not known for its earth quakes as the USGS readily admits. That agency considers Colorado an area of minor earthquake activity. Therefore, it was a little surprising when a large number of earthquakes began to occur in and around the Denver area in the 1960’s.

In 1961, a 12,000-foot well was drilled at the Rocky Mountain Arsenal, northeast of Denver, for disposing of waste fluids from Arsenal operations. Injection was commenced March 1962, and an unusual series of earthquakes erupted in the area shortly after.

It was 32 minutes after 4 a.m. on April 24 when the first shock of the Denver series was recorded at the Cecil H. Green Geophysical Observatory at Bergen Park, Colorado. Rated magnitude 1.5, it was not strong enough to be felt by area residents. By the end of December 1962, 190 earthquakes had occurred. Several were felt, but none caused damage until the window breaker that surprised Dupont and Irondale on the night of December 4. The shock shuffled furniture around in homes, and left electrical wall outlets hanging by their wires at Irondale.


Over 1,300 earthquakes were recorded at Bergen Park between January 1963 and August 9, 1967. Three shocks in 1965 — February 16, September 29, and November 20 — caused intensity VI damage in Commerce City and environs. […]

Another strong shock rumbled through the Denver area on November 14, 1966, causing some damage at Commerce City and Eastlake. Slighter rumblings (below magnitude 3.0) occurred throughout the remainder of 1966, and through the first week of April 1967.

Then, on April 10, the largest since the series began in 1962 occurred; 118 windowpanes were broken in buildings at the Rocky Mountain Arsenal, a crack in an asphalt parking lot was noted in the Derby area, and schools were dismissed in Boulder, where walls sustained cracks. Legislators quickly moved from beneath chandeliers in the Denver Capitol Building, fearing they might fall. The Colorado School of Mines rated this shock magnitude 5.0.

Boulder sustained minor damage to walls and acoustical tile ceilings on April 27, 1967, as result of a magnitude 4.4 earthquake. Then a year and half after the Rocky Mountain Arsenal waste dumping practice stopped, the strongest and most widely felt shock in Denver’s history struck that area on August 9, 1967, at 6:25 in the morning. The magnitude 5.3 tremor caused the most serious damage at Northglenn, where concrete pillar supports to a church roof were weakened, and 20 windows were broken. An acoustical ceiling and light fixtures fell at one school. Many homeowners reported wall, ceiling, floor, patio, sidewalk, and foundation cracks. Several reported basement floors separated from walls. Extremely loud, explosivelike earth noises were heard. Damage on a lesser scale occurred throughout the area.

During November 1967, the Denver region was shaken by five moderate earthquakes. Two early morning shocks occurred November 14. They awakened many residents, but were not widely felt. A similar shock, magnitude 4.1, centered in the Denver area November 15. Residents were generally shaken, but no damage was sustained. A local shock awakened a few persons in Commerce City November 25. Houses creaked and objects rattled during this magnitude 2.1 earthquake.

The second largest earthquake in the Denver series occurred on November 26, 1967. The magnitude 5.2 event caused widespread minor damage in the suburban areas of northeast Denver. Many residents reported it was the strongest earthquake they had ever experienced. It was felt at Laramie, Wyoming, to the northwest, east to Goodland, Kansas, and south to Pueblo, Colorado. At Commerce City merchandise fell in several supermarkets and walls cracked in larger buildings. Several persons scurried into the streets when buildings started shaking back and forth.

During 1968, ten slight shocks were felt in Colorado. Only one, on July 15, caused minor damage at Commerce City. In September of that year, the Army began removing fluid from the Arsenal well at a very slow rate, in hope that earthquake activity would lessen. The program consisted of four tests between September 3 and October 26. Many slight shocks occurred near the well during this period.

No one knew what was causing these numerous quakes. Well, no one in the general public knew. However, apparently the folks at the RMA had a clue as to why suddenly Denver and its environs was a hotbed for earthquakes.

The Rocky Mountain Arsenal deep injection well was constructed in 1961, and was drilled to a depth of 12,045 feet. The well was cased and sealed to a depth of 11,975 feet, with the remaining 70 feet left as an open hole for the injection of Basin F liquids. For testing purposes, the well was injected with approximately 568,000 gallons of city water prior to injecting any waste. However, when the Basin F liquids were actually introduced, the process required more time than anticipated to complete because of the impermeability of the rock. The end result was approximately 165 million gallons of Basin F liquid waste being injected into the well during the period from 1962 through 1966. […]

The injected fluids had very little potential for reaching the surface or useable groundwater supply since the injection point had 11,900 feet of rock above it and was sealed at the opening. The Army discontinued use of the well in Feb. 1966 because of the possibility that the fluid injection was triggering earthquakes in the area. The well remained unused for nearly 20 years.

Yes the Arsenal stopped injecting fluid into the well because there was a possibility it was causing earthquakes. Well, that’s the official Army spin, of course, since that excerpt is taken directly from the RMA’s own webpage “Fact Sheet.” Here’s what the USGS concluded:

Earthquakes induced by human activity have been documented in a few locations in the United States, Japan, and Canada. The cause was injection of fluids into deep wells for waste disposal and secondary recovery of oil, and the use of reservoirs for water supplies. Most of these earthquakes were minor. The largest and most widely known resulted from fluid injection at the Rocky Mountain Arsenal near Denver, Colorado. In 1967, an earthquake of magnitude 5.5 followed a series of smaller earthquakes. Injection had been discontinued at the site in the previous year once the link between the fluid injection and the earlier series of earthquakes was established. (Nicholson, Craig and Wesson, R.L., 1990, Earthquake Hazard Associated with Deep Well Injection–A Report to the U.S. Environmental Protection Agency: U.S. Geological Survey Bulletin 1951, 74 p.)

Read that last part carefully:

Injection had been discontinued at the site in the previous year once the link between the fluid injection and the earlier series of earthquakes was established. (Nicholson, Craig and Wesson, R.L., 1990, Earthquake Hazard Associated with Deep Well Injection–A Report to the U.S. Environmental Protection Agency: U.S. Geological Survey Bulletin 1951, 74 p.

In short, the RMA well drilled 12,000 feet deep and the fluid injection into that well by the RMA was responsible for the mass outbreak of earthquakes the Denver area experienced.

I remember the August 1967 earthquake very well. We lived roughly 20 to 30 miles away from the epicenter of the quake. I was 11 years old and the rumbling of our house woke me up. Our whole house shook, and many items fell off my desk in my room. Paintings and family pictures fell off our walls throughput the house. A few items were broken. We were fortunate though not to suffer any serious cracks to our home’s foundation. The main damage occurred in Northglenn, a suburb of Denver, NNE of our home:

The main damage occurred in Northglenn, a northern suburb of Denver, but minor damage occurred in many area towns. At Northglenn, concrete pillars were damaged at a church; foundations, concrete floors, and walls cracked; windows broke; and tile fell at a school. At one residence, a piano shifted about 15 cm and a television set overturned. Some bricks fell from a chimney in downtown Denver, damaging a car. This was the largest of a series of earthquakes in the northeast Denver area that were believed to be induced by pumping of waste fluids into a deep disposal well at the Rocky Mountain Arsenal. The Colorado School of Mines recorded more than 300 earthquakes from this zone during 1967. Felt north to Laramie, Wyoming, south to Pueblo, west to Vail, and east to Sterling.

Here’s photograph that shows some of the damage that was done to a concrete pillar to a highway overpass.

That kid in the picture actually looked a lot like me at the time. Same haircut, same oddly striped shirt, same look of befuddlement.

Funny, but the large number of earthquakes the Denver area experienced subsided a few years after the Rocky Mountain Arsenal stopped pumping waste water into the well. Just as the earthquake swarm in Arkansas appears to have stopped after hydrofracking operations were suspended there earlier this year.

LITTLE ROCK, Ark. (AP) — The number and strength of earthquakes in central Arkansas have noticeably dropped since the shutdown of two injection wells in the area, although a state researcher says it’s too early to draw any conclusions.

“We have definitely noticed a reduction in the number of earthquakes, especially the larger ones,“ said Scott Ausbrooks, geohazards supervisor for the Arkansas Geological Survey. “It’s definitely worth noting.“

The Center for Earthquake Research and Information recorded around 100 earthquakes in the seven days preceding the shutdown earlier this month, including the largest quake to hit the state in 35 years — a magnitude 4.7 on Feb. 27. A dozen of the quakes had magnitudes greater than 3.0. In the days since the shutdown, there have been around 60 recorded quakes, with only one higher than a magnitude 3.0. The majority were between magnitudes 1.2 and 2.8.

The two injection wells are used to dispose of wastewater from natural-gas production. One is owned by Chesapeake Energy, and the other by Clarita Operating. They agreed March 4 to temporarily cease injection operations at the request of the Arkansas Oil and Gas Commission.

The commission said preliminary studies showed evidence potentially linking injection activities with nearly 1,000 quakes in the region over the past six months.

So if someone says that hydrofracking and fluid injection into those wells absolutely didn’t cause the earthquakes yesterday (such as some of the commentators to this rec list diary by kavips claim, well, I would treat that conclusion with a fair amount of skepticism at this time. I can assure you of this much. Human activities which pump large volumes of fluids deep underground have been shown to cause earthquakes according to the US Geological Service. Large numbers of earthquakes were shown to have occurred in Colorado in the 60’s because of the pumping of millions of gallons of waste fluids into a well maintained by the Rocky Mountain Arsenal.

Therefore, to claim that hydrofracking activity, which also pumps massive volumes of fluids deep underground, had nothing to do with yesterday’s earthquakes would be jumping to a conclusion that is unwarranted at this time. We don’t know, but it is a legitimate hypothesis that should be followed up and looked at very carefully considering the past history of fluid injection into wells drilled deep underground that led to earthquakes.