Man-made earthquakes are real, they are proliferating across the U.S. Midwest, and the oil and gas industry is “almost certainly” responsible.
Those are the latest conclusions scientists with the U.S. Geological Survey will be discussing at a seismology conference next week. Their more reassuring message: none of the man-made tremors have been big enough to knock down any buildings — so far.
The nation’s midsection is typically quiet, geologically speaking. So when USGS seismologist Bill Ellsworth noticed an unusual number of earthquakes in that region about 12 years ago, he wanted to know why.
Ellsworth, who is based at the USGS office in Menlo Park, Ca., used ultra-sensitive quake-sensing technology to track mid-western tremors over the ensuing years. Then, in 2009, the rumbling increased.
“After that time, things really began to take off, and that’s what really caught our attention,” Ellsworth told NPR’s Christopher Joyce. “It is really quite surprising.”
Ellsworth and his colleagues watched the number of quakes jump from a steady background of 20 tremors a year to 50 in 2009, 87 in 2011 and a whopping 134 last year. Clearly, something strange was going on.
The thick basement rock underlying the U.S. Midwest is full of faults, just like basement rock everywhere. But earthquakes only happen when something changes the stress regime enough to unlock those faults. In quake-prone places such as California and Japan, the edges of tectonic plates are shoving past each other. Near active volcanoes, magma presses on the rocks as it pushes its way up from below.
“A naturally-occurring rate change of this magnitude is unprecedented outside of volcanic settings or in the absence of a main shock, of which there were neither in this region,” Ellsworth notes in the summary of his conference presentation. That is why he and his team conclude that the startling increase is “almost certainly man-made.”
That’s where the oil and gas industry comes in. From experiences with dams, scientists known that one man-made way to unlock a fault is to lubricate it. In the past year, several studies have blamed a natural-gas-extraction technique known as fracking for quakes. That process requires prospectors to pump billions of gallons of water a year deep underground. Forced underground under high pressure, the water cracks open the rocks and releases natural gas trapped in small pockets within them.
But Ellsworth’s closer inspection revealed that many of the new quakes were clustering not around the drilling sites but instead around wastewater wells, the much deeper holes where companies dump the salty frack water once it has been used.
“Waste wells have been around for decades. There are tens of thousands of waste wells in the country, but very few quakes,” NPR’s Christopher Joyce explained in his interview with Ellsworth. “What’s changed is that the gas industry is using—and disposing of—more water. Waste wells are often deeper than gas drilling wells, down into basement rock where faults are more common.”
Scientists outside of the current study point out that we don’t know with absolute certainty that a given wastewater well caused a particular earthquake. But it seems we know plenty to merit keeping a very close eye on the situation.
The largest quakes clustering around wastewater wells in Ellsworth’s study were only a magnitude 4, enough energy to impart a strong jolt to anyone standing right above it but not enough to damage a building. The public may not be so generous if larger quakes start being implicated.
In January, President Obama rejected an application to build the full Keystone XL oil pipeline, intended to transport Canada’s oil sands some 2,000 miles to refineries near the Gulf of Mexico. Yet on Thursday he stood in front of acres of stacked pipeline pieces in Cushing, Okla., and declared that expedited construction of the southern leg of the pipeline is a priority for his administration.
“And as long as I’m president, we’re going to keep on encouraging oil development and infrastructure, and we’re going to do it in a way that protects the health and safety of the American people,” he said to an invited audience of about 200 people. “We don’t have to choose between one or the other, we can do both.”
Not everyone is convinced we can really have it both ways. Among the doubters is Becky Bond, political director of Credo Action, part of a coalition of environmental groups that issued a joint statement of opposition.
“The president needs to prove that his initial rejection of Keystone XL wasn’t simply a ploy to placate the environmental voters who dared to hold him to his own rhetoric about the need for real leadership on climate and our fossil fuel dependence,” Bond told The New York Times.
This news broke the same day another story in The New York Times asserted that the U.S. is inching its way toward its long-touted dream of energy independence. OK, but at what cost?
At face value, it seems like good news that the U.S. imported only 45 percent of the liquid fuels it used in 2011, down from a record high of 60 percent in 2005. An uplifting part of the reason for this turnabout is that Americans are pumping less gasoline (not only because of the recession and high gas prices but also because they are also driving fewer miles in more fuel-efficient vehicles). But that’s not all that’s going on.
Reporters Clifford Krauss and Eric Lipton Krauss point out two other key factors: “ … industry-friendly policies started by President Bush and largely continued by President Obama — many over the objections of environmental advocates — as well as technological advances that have allowed the extraction of oil and gas once considered too difficult and too expensive to reach.”
Indeed, areas of west Texas and eastern New Mexico are experiencing a new energy rush, with prosperity spilling far beyond the oil fields: “In nearby towns, petroleum companies are buying so many pickup trucks that dealers are leasing parking lots the size of city blocks to stock their inventory. Housing is in such short supply that drillers are importing contractors from Houston, and hotels are leased out before they are even built,” Krauss and Lipton report.
Yet every boom has its loser, and in this case it is no doubt the environment. Fracking requires huge quantities of water, which is hard to come by in the desert. If fracking continues expanding, water experts say aquifers in the desert area could run dry. And that’s just one among the litany of concerns.
Before you go hoping that the silver lining of this story might be cheaper prices at the pump, recall the complications of a global market. Even though Americans and Europeans are consuming less oil, the rest of the world is on a steep rise in consumption. That critical factor, combined with the U.S.’ current political standoff with Iran and supply disruptions in Africa, easily offsets the impact of increased domestic supply.Source