Fracking is the abbreviated word for “hydraulic fracturing” — the widening of fractures in a rock layer caused by the high-pressure injection of chemicals with water.
While hydraulic fractures form naturally, as in the case of veins or dikes, there is also a kind that is human-induced. Induced fracking is industrial hydraulic fracturing that widens or creates fractures to speed up the migration of gas and petroleum from source rocks to reservoir rocks. This process is used to release petroleum, natural gas, or other substances for extraction, by creating fractures from a wellbore drilled into reservoir rock formations.
As the incidence and intensity of earthquakes in America and across the globe seem to have increased in recent months, speculations abound on the Internet that fracking may be the cause of earthquakes. Those speculations, of course, are dismissed by the Establishment Media as dastardly “conspiracy theories.” Two days ago, however, none other than Reuters reported that U.S. government geologists are now saying exactly the same thing — that the recent swarms of earthquakes in central United States may be human caused.
The number of earthquakes in the central United States rose “spectacularly” near where oil and gas drillers disposed of wastewater underground, a process that may have caused geologic faults to slip, U.S. government geologists report.
The average number of earthquakes of magnitude 3 or greater in the U.S. midcontinent – an area that includes Arkansas, Colorado, Oklahoma, New Mexico and Texas – increased to six times the 20th century average last year, scientists at the U.S. Geological Survey said in an abstract of their research.
The abstract does not explicitly link rising earthquake activity to fracking – known formally as hydraulic fracturing – that involves pumping water and chemicals into underground rock formations to extract natural gas and oil. But the wastewater generated by fracking and other extraction processes may play a role in causing geologic faults to slip, causing earthquakes, the report suggests.
“A remarkable increase in the rate of (magnitude 3) and greater earthquakes is currently in progress,” the authors wrote in a brief work summary to be discussed Wednesday at a San Diego meeting of the Seismological Society of America. “While the seismicity rate changes described here are almost certainly manmade, it remains to be determined how they are related to either changes in extraction methodologies or the rate of oil and gas production,” the abstract said.
From 1970 through 2000, the rate of magnitude 3 or greater quakes was 21 plus or minus 7.6 each year, according to USGS figures. Between 2001 and 2008, that increased to 29 plus or minus 3.5. But the next three years saw the numbers increase “much more spectacularly,” said Arthur McGarr, of the geologic survey’s Earthquake Science Center in California: 2009 had 50, 2010 had 87 and 2011 had 134 such events.
“We don’t know why, but we doubt that it’s a natural process, because in nature, the only time you see such a big increase is during an aftershock sequence (with a series of quakes) or in a volcanic setting where you often get swarms of earthquakes due to magmatic activity,” McGarr said by telephone.
EXPLORING THE LINK
When swarms of quakes occurred in Colorado and Oklahoma last year, the U.S. Environmental Protection Agency asked the geologic survey to investigate possible links to energy extraction in the area.
Among other sites, they examined an August 2011 earthquake centered around Trinidad, Colorado, near the New Mexico border, that registered a magnitude of 5.3, said McGarr, a co-author of the abstract.
That quake “turned out to be really close to two of the highest injection volume waste water disposal wells in the field,” McGarr said. “So that gives us quite a strong hint that these earthquakes are being triggered by these wastewater disposal facilities.”
There were different responses on either side of the Colorado-New Mexico line, he said. New Mexico, where the policy was to inject all wastewater underground, experienced more earthquakes than Colorado, where some wastewater is disposed at the surface.
America’s Natural Gas Alliance, which represents major energy companies involved in natural gas fracking, said it was difficult to conclude anything based on an unpublished abstract. “We are committed to monitoring the issue and working with authorities where there are concerns, but it should be noted that currently there is no scientific data associating hydraulic fracturing with earthquakes that would cause damage,” ANGA spokesman Dan Whitten said in an email.
The disposal of wastewater underground, called injection, has long been known to have the potential to cause earthquakes, the Interior Department said in a blog post here. What is new is the ability to precisely locate earthquakes of magnitude 3 or greater (magnitude 3 is recognized as the threshhold for detection) and a signature shape of the waves on a seismogram indicating a shallow quake, McGarr said. Human-induced quakes are typically quite shallow, he said.
“Human-induced quakes are typically quite shallow.”
That’s small comfort for the millions of Americans living in central United States in the New Madrid Seismic Zone — a 150-mile long fault system spanning five states. Most of the seismicity is located between 3 and 15 miles beneath the Earth’s surface.
The zone had four of the largest North American earthquakes in recorded history, with moment magnitudes estimated to be as large as 8.0, all occurring within a three-month period between December 1811 and February 1812.
In a report filed in November 2008, FEMA ( Federal Emergency Management Agency) warned that a serious earthquake in the New Madrid Seismic Zone could result in “the highest economic losses due to a natural disaster in the United States,” further predicting “widespread and catastrophic” damage across Alabama, Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri and particularly Tennessee. The earthquake is expected to also result in many thousands of fatalities, with more than 4,000 of the fatalities expected in Memphis alone. The USGS [U.S. Geological Society] recently issued a fact sheet reiterating the estimate of a 10% chance of a New Madrid earthquake of magnitude comparable to those of 1811-1812 within the next 50 years.
Now we know why the federal government coordinated an earthquake drill at 10:15 am on April 28, 2011, of precisely the 8 states who are in the New Madrid Seismic Zone. It was the largest earthquake drill in Central U.S. history.
Below is a video on the New Madrid Fault Line: