Geologists have confirmed that the controversial process of fracturing rock to release trapped oil and gas reserves, otherwise known as 'fracking', can cause earthquakes. The rock is fractured using highly pressurized 'injections' of water, sand and other materials which creates fissures in the rock enabling the extraction of the gas and oil deposits. Chemicals such as hydrofluoric acid are also used to dissolve shale rock.
When fracking started near Youngstown, Ohio, small earthquakes began to be felt. The area had never previously experienced an earthquake, yet a tremor was recorded there just thirteen days after the Northstar 1 injection well opened nearby in 2010 and began pumping waste water underground The town located over one of the regions thought to have one of the most plentiful supplies of underground gases, the Marcello Shale.
Following the first quake in 2010, a further 109 earthquakes occurred in and around Youngstown, with the most powerful of these registering 3.9 on the Richter scale; it was also noted that no tremors were recorded in the area during periods when the well was temporarily inactive. A recent scientific investigation, published in the journal Geophysical Research Letters, linked all of the quakes to the Northstar well, which was shut down after the largest tremor. No further seismic activity has been recorded since.
Evidence which suggests that fracking can cause a variety of unpleasant and dangerous consequences has made this a very emotive subject and tensions are running high. In the UK, a Member of Parliament has made history by being arrested during demonstrations against the procedure, and, bowing under pressure from angry citizens, some US states, such as California, have begun to regulate the process by requiring companies to obtain permits, and to monitor air and groundwater supplies with independent scientific studies.
The concerns regarding fracking are manifold: aside from the by-products of the process which include large amounts of waste water, the bulk of which is pumped underground and thought to cause underground disturbance and erosion, environmentalists also fear that the chemicals used can leak into water supplies. Perhaps most worrying of all is that the process of creating fissures and/or the disposal of waste water has been linked to an increase in earthquakes in areas around fracking sites.
The study, led by seismologist Won-Young Kim and conducted at Columbia University's Lamont-Doherty Earth Observatory in Palisades, New York, found evidence that the injections of waste water had triggered activity in an ancient fault near the well. Kim said that it was not necessarily the fracking process itself which caused the problems, however, but the method of disposing waste water underground. He went on to comment that problems of this type were likely to be rare, and that the researchers had not discovered any similar issues with the other 177 waste water wells in the Ohio area.
The study suggested that the way to avoid similar problems in the future was to improve methods of detecting faults before drilling commenced. "We need to find better ways to image hidden subsurface faults and fractures, which is costly at the moment," Kim said. "If there are hidden subsurface faults near the injection wells, then sooner or later they can trigger earthquakes."
Youngstown is not the only area to have suffered such earth-shaking side-effects from fluid injections: the biggest earthquake ever recorded in Oklahoma, measuring 5.6 magnitude, is also thought to be attributable to gas extraction in the surrounding area; if this was proved it would be the largest fracking-related quake to date. Over 180 smaller tremors which occurred in Texas between 2008 and 2009 were also thought to be caused by underground fluid injection.
Environmentalists would argue that earthquakes are only one of the unpleasant side-effects resulting from fracking, though in an area like California, which resides precariously on an already active fault line, this surely has to be one of the major concerns. Residents near to fracking sites have also complained of other issues such as contaminated drinking supplies causing sensory and neurological disorders, and escaping toxic fumes leading to an increase in respiratory illnesses.
Fracking is tremendously valuable economically, and is a major contributor to the growing energy independence of the United States. Countries around the world are racing to find areas to apply the technology, and energy-poor countries such as China expect to gain access to substantial energy reserves by using the process. To illustrate its value, the Marcello Shale alone could yield up to 489 trillion cubic feet (13.8 trillion cubic meters) of natural gas, more than 440 times the annual gas usage of New York State.
It remains a very controversial process, and governments must decide whether the potential for inexpensive energy production outweighs the risk to human health. Concern about the practice may also extend outside of this planet, as there have been reports of increased UFO activity around fracking sites.
Unknown Country has been tracking the debate for years, and will continue to bring you insights from the latest reports.