Wednesday, April 11, 2012

Fracking, wastewater injection wells, and earthquakes

Today on NPR it was reported that, "The U.S. Geological Survey will soon confirm that the oil and gas industry is creating earthquakes, and new data from the Midwest finds that these man-made quakes are happening more often than originally thought."

The story, entitled "Quakes caused by waste from gas wells, study finds" reports on the analysis of USGS seismologists including Bill Ellsworth, who noticed that records showed that relatively minor earthquakes in the middle of the North American continent (far from plate boundaries) were increasing dramatically in frequency beginning in 2009 and every year after that (from 50 in 2009, to 87 in 2010, to 134 in 2011).

Seismologists suspect that the tremendous increase in hydraulic fracturing -- a new technique to obtain natural gas trapped in deep shale, that has led to a natural gas boom in North America in the past five years -- may be responsible.

Fracking entails the injection of tremendous amounts of water into deep wells which go many thousands of feet down and then turn horizontal. The water doesn't stay down there forever, however -- it comes back up, and is then either processed and recycled for more fracking operations, or disposed of. While wastewater was often originally simply discharged into rivers in the early years of fracking, it is increasingly being disposed of by injecting it deep into the earth -- sometimes even deeper than the fracking wells themselves, which can be 7,000 or 8,000 feet deep (at times even deeper than that).

Deep wastewater injection wells have been used for decades to dispose of treated wastewater from municipal and industrial sources in the United States, but fracking operations produce vastly greater volumes. Scientists now suspect that the new volumes of wastewater may be unlocking existing faults and triggering earthquakes in places like Texas and Ohio which rarely experienced earthquakes in the past.

Today's report that the USGS has concluded that such deep and high-volume water injection can lead to earthquakes should come as no surprise to readers of this Mathisen Corollary blog or to followers of Walt Brown's hydroplate theory. Nearly a year ago, on May 4 of 2011, a post entitled "Earthquakes far from quake boundaries" discussed the evidence that, while it is clear that powerful geological forces are responsible for earthquakes, it is also increasingly clear that these forces are not generated by drifting tectonic plates upon a circulating molten mantle the way that conventional tectonic theory asserts.

That post pointed out that the hydroplate theory of Dr. Brown does a much better job of explaining "why earthquakes can be caused by injecting high-pressure water deep into the ground and by filling huge man-made reservoirs with water (as happened in India in 1967 and 1998 and in China in 2008 and possibly 2010)." It also noted the "possibility that the injection of high-pressure water into the ground could be responsible for earthquakes in Arkansas."

Not long after that post, another published June 8 of last year entitled "Back from the Bay Area and the San Andreas Fault" discussed in even greater detail the hydroplate theory's explanation for the existence of faults and the initiation of shallow earthquakes near faults (the hydroplate theory satisfactorily explains the existence of two distinct mechanisms for the initiation of shallow earthquakes which typically originate less than 100 miles below the surface, and deep earthquakes which originate at depths greater than 250 miles -- the tectonic theory has a very difficult time explaining the existence of these two types of earthquakes, especially deep earthquakes).

That post concluded with the statement that, "This reasoning would also explain why the process of forcing water deep into the ground at high pressures (such as for hydraulic fracking or for the harnessing of geothermal energy) has been alleged to start man-made earthquakes (see for example the article and links at this site, among many others on the web)."

Later last year, on November 7, a post entitled "Asteroids, earthquakes and lions -- oh my" discussed a series of earthquakes in Oklahoma that struck within the course of a weekend. Although news reports explained that "scientists are puzzled by the recent seismic activity," the county hit by the quakes had 181 injection wells. The post noted that, while scientists operating under the conventional tectonic theory might be puzzled by this connection, the hydroplate theory explains the origin of these earthquakes, and that Dr. Brown's published texts had been warning for many years that injecting water deep into the earth can be expected to trigger earthquakes if his theory is correct (he had written such warnings long before these recent confirmations began to crop up).

You can visit Dr. Brown's website and read his entire book about the hydroplate theory online for free. To focus on his discussions of the causes of the countless fractures in the earth's crust and the origins of earthquakes, check out his detailed examination on this page, followed by the subsequent explanation on this page.

Here's the connection between the hydroplate theory and the wastewater injection earthquakes. Shallow earthquakes are caused by forces acting along existing faults, according to the hydroplate theory and the tectonic theory, but these forces have different origins and the origin of the faults themselves have different explanations under each theory. The very existence of the countless faults in the earth's crust and mantle is better explained by the hydroplate theory, which argues that the tremendous mass imbalances in the earth during the events surrounding a global flood created the countless faults we find today (the major forces that led to faulting involved the dramatic rise of the basement mantle under what is today the Atlantic Ocean when the escaping water eroded overlying crust and removed the weight of that crust, followed by an even more dramatic collapse of the area that now form the basin of the Pacific Ocean and Indian Ocean, as mass moved towards the Atlantic, accompanied by tremendous friction, melting, and magma production). The tectonic theory argues that the faults on the earth are produced by the pressure of tectonic plate movement, but Dr. Brown points out that many faults are parallel to the movement of plates, many are perpendicular to the movement of plates, and many even intersect with one another -- in other words, their origin and direction are not easy to explain via plate movement.

Similarly, the slippage of faults -- especially those located very far from plate boundaries -- is not well explained by the tectonic theory. However, the hydroplate theory explains it very coherently, and in a way that is consistent with the suggestion that high-pressure injection of water deep underground near faults could trigger earthquakes.

Dr. Brown explains the deep forces at work which cause earthquakes:
After the flood, magma under the Pacific floor, but above the crossover depth, erupted onto the Pacific floor. (To a much lesser extent, eruptions continue today, so in those places, ocean temperatures rise temporarily, a phenomenon called El NiƱo.14) Magma below the crossover depth drains down into the outer core, so the outer core is slowly growing today! Simultaneously, melting is shrinking the total volume below the crossover depth, so the crust is compressing like the wrinkling skin of a drying (shrinking) apple. Also, the continents, thickened during the compression event, are still sinking into and laterally displacing the mantle. So the mantle is being squeezed downward from above and upward by the growing outer core. Mantle volume is also being lost primarily from the Pacific mantle by draining below the crossover depth and by eruptions above the crossover depth. Therefore, the mantle is shifting an inch or so a year, in general, toward the Pacific to replace that escaping volume. [See Figure 91 on page 165.] These movements and stresses produce earthquakes. Slowly shifting continents led to the mistaken belief that the entire solid mantle somehow circulates as if it were a liquid—and, over millions of years, drifted continents over the face of the earth. [To read this passage in Dr. Brown's book, go to this page, to a paragraph in the section entitled "Deep Movements During the Flood Phase"].
These forces create frictional heating along faults. From there, Dr. Brown explains:
frictional heating along the fault melts the grain-sized minerals with the lowest melting temperatures, causing them to expand, because they were above the crossover depth. (Remember: Tiny movements at the extreme pressures deep in the earth create great heat and melting.) Minerals with higher melting temperatures remained solid, maybe for decades, thereby encasing and trapping the tiny droplets of melted rock.

As more frictional heat “soaked” very slowly into the rock on both sides of the fault, the previously encased droplets of melt began to leak. Paths opened up for the expanding melt to escape upward buoyantly, allowing the highly compressed solid “scaffolding” (surrounding the focus and composed of the minerals with the highest melting temperatures) to become unstable and begin to collapse. Frictional heating instantly became extreme, so all nearby minerals suddenly melted. The result: a powerful earthquake. [To read this passage in Dr. Brown's book, go to this page].

So, Dr. Brown believes that most fault slippage occurs because the fault is unlocked due to the sudden liquification of rock along the fault due to frictional heat buildup over time. However, he notes that in addition to melted rock (magma) creating a fault movement, high-pressure water could do the same thing. In note 25 on this page of his book, he says:

Shallow earthquakes, in addition to the mechanism explained in Figure 88, may involve another phenomenon. Trapped subterranean water, unable to escape during the flood, slowly seeps upward through cracks and faults formed during the crushing of the compression event. (Seismographs on the Pacific Ocean floor have measured tremors from such seepings.)11 The higher this water migrates through a crack, the more the water’s pressure exceeds that in the walls of the crack trying to contain it. Consequently, the crack spreads and lengthens. (So, before an earthquake, the ground often bulges slightly, water levels sometimes change in wells, and geyser eruptions may become more irregular.) Simultaneously, stresses build up in the crust, again driven ultimately by gravity and mass imbalances produced by the flood. Once compressive stresses have risen enough, the cracks have grown enough, and the frictional locking of cracked surfaces has diminished enough, sudden movement occurs. Water acts as a lubricant. (Therefore, large temperature increases are not found along the San Andreas Fault.) Sliding friction instantly heats the water, converts it to steam at an even higher pressure, and initiates a runaway process, one type of shallow earthquake.

This explanation reveals the reason that the injection of high-pressure water deep underground by human activity can also create a similar result.

In note 63 on this page of his book, Dr. Brown discussed the potential dangers of a proposed US government plan to drill a five-and-a-half-mile deep hole in an area of the southern Appalachians, stating that "Such a drilling project could be extremely dangerous. [. . .] major earthquakes could occur." In that discussion, Dr. Brown was concerned about the possible release of water trapped deep beneath the Appalachians, as the rapid removal of water could also trigger earthquakes (the hydroplate theory proposes that water was once trapped beneath the crust and it escaped violently to cause a temporary worldwide flood; according to this theory, we should expect to find some of the remnant water still trapped deep beneath major mountain ranges, and in fact there is some evidence to suggest that this prediction of Dr. Brown is in fact the case). Interestingly enough, in the NPR story cited above, a different seismologist, Chris Frohlich of the University of Texas, notes that removal of massive amounts of subterranean oil and gas may also lead to quakes.

The fact that scientists are now reaching conclusions consistent with the hydroplate theory, especially the possibility of a connection between the injection of water deep into the earth and the initiation of shallow man-made earthquakes, provides yet another data point in favor of the hydroplate theory of Dr. Walt Brown. In light of this new development, and in light of the hydroplate theory's superiority in explaining the even more powerful and dangerous deep earthquakes (along with the hope it offers for early warning prior to some major earthquakes), doesn't it seem obvious that professional geologists should seriously consider the merits of this theory?


Sidenote: the fact that fracking (or, more precisely, the disposal of wastewater from fracking) may cause earthquakes does not of itself automatically mean that fracking should not be used to obtain oil and natural gas. First, fracking wastewater can be recycled and reused for other fracking operations, rather than injected into wastewater wells, and such recycling is becoming more and more common. Second, as mentioned in the NPR discussion, most of these wastewater-associated earthquakes are in the range of 3.0 magnitude -- which is difficult to distinguish from the rattling that takes place when a large truck drives down your street. Some people live in parts of the globe that experience many such earthquakes as a matter of course. It is certainly possible to argue that the benefits of any human activity must be weighed carefully against the costs, and the costs weighed against the benefits. It is not an automatic "slam dunk" either way. The purpose of the above discussion is not to argue for or against fracking, but to argue that the recent conclusion by USGS scientists and other seismologists about a connection between wastewater injection and shallow earthquakes in the middle of the United States appear to be consistent with the published predictions of the hydroplate theory.