Why The Economic Over Exploitation Of Resources Is Causing Human-Induced Earthquakes
Geoscience Weekly: Exploring Earth's Phenomena VII
This weekly newsletter delves into a different captivating topic from the world of geoscience, exploring Earth’s fascinating phenomena in bite-sized, easy-to-understand segments each week.
Monday 25th of March, as of last week we looked in detail into the formation of earthquakes which arise due to interacting plate boundaries but it’s also possible that our over exploitation of natural resources can lead to human-induced earthquakes. For example, the 2011 Oklahoma earthquake with a magnitude of 5.8 which occurred near Prague was caused due to a continuous 20 yearlong injection process of wastewater into porous deep formations. A human process. This is just one of many examples of human-induced earthquakes which can be just as dangerous as naturally occurring earthquakes. We will even look at hypothetical devices/systems known as tectonic weapons which can trigger many seismic events and is a source for many conspiracy theories. However, most human-induced earthquakes occur from industrial industries — along with most environmental problems — such as fracking and wastewater disposal. We will go into detail about how fracking works and why it can cause earthquakes going into the advantages and disadvantages.
Before we get into fracking let’s take a quick detour and investigate tectonic weapons and some of the current potential tectonic weapons which could be used against us right now. Although the idea of tectonic weapons can be considered imaginary it will still be interesting to dive into the geopolitical topic and see if something like this could be possible.
Tectonic Weapons
As mentioned earlier tectonic weapons are devices/systems which could trigger earthquakes, volcanoes and other seismic events caused by a weapon which could create a powerful charge of elastic energy or a nuclear explosion in which the epicentre of the explosion would be the source of elastic energy. For example, the 1968 Faultless underground nuclear test hosted several high-yield nuclear tests mainly associated with anti-ballistic missile systems. The problem with these tests was that the surrounding geology was unsuitable meaning that the nuclear tests caused faults to slip up to 40 km away. The United States Geological Survey claim that these tests caused a 1,200 m fresh fault rupture however earthquake induced explosions are often much smaller than the actual explosion itself. There are viable options although like the Project Seal programme which was attempted during WW2 by New Zealand to create tsunami bomb. So, who knows if organisations around the world have access to weapons of this kind.
Fracking
Fracking formally known as hydraulic fracturing is a drilling method used to extract oil and natural gas from the Earth. Fracking involves blasting large quantities of water, chemicals and sand into impermeable rock formations known as ‘tight’ rock which lock in oil and gas. Therefore, some of the resources extracted are known as ‘tight oil’ and ‘tight gas’. This impermeable rock ‘tight rock’ is hard shale rock. Shale rock is a fine-grained sedimentary rock that is formed from the compaction of silt and clay, and it is very fissile (the rock readily splits into thin pieces) and laminated (made up of thin layers). Most natural gas and oil deposits come from black organic shales as black shales contain organic materials that breaks down to form oil and natural gas. The black colour of these shales comes from minuscule particles of organic matter that were mixed with the mud during the shale’s formation. As the mud was buried and heated deep within the Earth, some of the organic material underwent a transformation into oil and natural gas.
The fracking process begins with the vertical drilling of a well which can be up to a mile deep. Steel pipes known as casings aided with cement helps to stabilise the well while also preventing water contamination. Horizontal drilling is then paired with fracking which enables more contact with rock formation. The fluid is then blasted into the well at high pressure which creates fractures in the rock. These fractures occur when plastic balls are forced down the well which open sleeves in the pipe exposing holes. The fluid shoots through the holes fracturing the rock. The fractures in the rock allow oil or gas to flow into the well. The fluid is composed up of 97% of water and as much as several million gallons of water on a single well.
Earthquakes and Consequences
Earthquakes occur when the ground is subjected to so much force that it fractures. The elevated pressure from the liquid alters the stress on nearby geological faults and lubricates their surfaces, occasionally causing an earthquake. In the UK, the rocks are already close to their breaking point, making them susceptible to earthquakes triggered by additional pressure. However, most earthquakes are caused by the disposal of waste fluids which are a by-product of oil production and fluid injection. Wastewater disposal wells often operate for extended periods and inject significantly larger volumes of fluid compared to the hydraulic fracturing process. As a result, they have a higher likelihood of triggering earthquakes. The fluid injected at depth can occasionally form hydraulic connections with faults. In such cases, the increased fluid pressures within the fault counteract the frictional forces, thereby increasing the likelihood of earthquakes occurring along these faults. Some of these man-made earthquakes have been large enough to cause property damage and injuries.
Fracking also has many other environmental and human health risks. Exposure to pollution resulting from fracking activity can result in various adverse short-term and long-lasting health impacts. Short-term exposure to these pollutants has been associated with symptoms such as headaches, coughing, nausea, nosebleeds, skin and eye irritation, dizziness, and shortness of breath. Groundwater contamination is also a very prominent problem which arises from fracking usage. The oil and gas industry produces vast quantities of wastewater, consisting of flowback (used fracking fluid), produced water (naturally occurring water that is released with the oil and gas), and various naturally occurring contaminants. These contaminants include heavy metals, salts, toxic hydrocarbons like benzene, and radioactive materials such as uranium. If not properly managed, this wastewater can infiltrate and pollute the environment.
Conclusion
In conclusion, fracking is a dangerous practice which can have significant implications for environmental sustainability. One such concern is the occurrence of human-induced earthquakes linked to the injection of wastewater into disposal wells. This calls for higher levels of regulation and monitoring to regulate the risks. Moving forward we do need a balanced approach that considers both energy needs and environmental protection for fracking to be a sustainable practice. Fracking can be sustainable if enough money is spent to keep it safe however humans’ economic over-exploitation for resources will make sure this doesn’t happen.
Thank You
Thank you for reading, all information is taken from reputable sources and are linked below. All images are free to use under copyright laws.
National Geographic ‘ USGS ‘ NRDC ‘ The Center For Land Use Interpretation ‘ Geology.com ‘ Fractracker ‘ National Library Of Medicine