Earlier last week, two leading academics at Glasgow University released an article in the Quarterly Journal of Engineering that sited current limits for earthquakes in Hydraulic Fracturing were discouraging investment.
Dr. Rob Westaway and Professor Paul Younger stated restrictions on vibrations were so strict that if applied would even prevent buses from passing homes. The scholars also said that threats of serious earthquakes by fracking activity, was minimal compared to previous fears.
Recently, there has been much disagreement about the use of hydraulic fracturing for natural gas extraction. Dubbed “the cleanest of the fossil fuels”, fracking is a technique aimed at recovering gas and oil from shale rock. As the name implies, fracking relies on tons of water, both in the fluid injected into the shale and at the back end as flowback. Generally the flowback water or “formation water” that is left as a derivative, isn’t usable, much less drinkable and cannot be poured back into streams (although this too has happened), and must be rid-of in other ways.
Currently, only a few U.S states make the effort to filter the flowback water so that it can be reused. The most common, and cost-efficient disposal method, is injecting it deep within the earth’s surface, into huge underground wells. There has been much speculation about what happens after.
A growing number of scientists have suggested that the chemicals found in the by-product could trigger earthquakes, by swelling underground pressures and loosening existing fault lines. These so-called “earthquake swarms” have occurred in places not prone to movement, yet there’s been a rise in both magnitude and frequency of quakes in Arkansas, Ohio, Colorado and Texas. Scientists have now come to a consensus that the quakes are directly linked to injection wells.
There are more than 680,000 underground wastewater injection wells in the United States at present. According to the 2010 UIC Well Inventory, more than 150,000 are shooting industrial fluids below ground. What’s more, scientists and federal regulators acknowledge that they do not know how many of these sites are operating safely — meaning there’s no real way to assess leakages.
An article published by Mother Jones last year focused on the November 2011 Oklahoma earthquake that measured 5.7 on the Richter scale- the largest ever recorded in Oklahoma history. Retired Veteran Joe Reneau and his wife Mary said the impact on their home was so strong; their 28-foot chimney fell through the roof and straight into their living room. The couple has since abandoned notions to rehang family photos, for fear of another shattering quake.