Earthquakes are classified under natural calamities, as they are primarily caused due to the movement of tectonic plates. This was true a few centuries back, but things have changed with increased human interference in nature. There’s significant evidence to link earthquakes to human activity. To understand if earthquakes can be mad-made, here are some important things to know.
A good example will be Hoover Dam that had witnessed increased seismic activity when it was getting filled with water for the first time. It is to note that before construction of the dam, there was no seismic activity in the region.
Moreover, the level of seismic activity corresponded with the increase in water level. Thankfully, none of the shocks were big enough to damage the dam. Max recording was magnitude 5 on Richter scale. Experts opine that water pressure leads to changes in the crust below, which in turn creates earthquakes.
Injecting liquid into earth
When large amounts of liquid are injected deep into the earth’s crust, it can lead to earthquakes. An example comes from 1961, when US Army had drilled a 12,000-foot deep well to dispose toxic waste into the earth’s crust. Around 165 million gallons were pumped into the hole.
Subsequently, an earthquake was reported, which many experts attributed to the pumping of liquid into the earth’s crust. The liquid is likely to have created stresses on the rocks, which in turn had caused the earthquake. After the earthquake, the Army decided to stop the operation.
Millions of tons of coal are being mined every year from deep inside earth. Along with coal, a large amount of water also needs to be pumped out in most mines. This creates a significant change in mass of the region. It starts to affect the stresses within the rock formations, which can lead to earthquakes. It is estimated that around 50% of man-made earthquakes are due to mining operations.
Pumping out oil and natural gas from deep wells can lead to stresses along the rock formations. A relevant example is natural-gas field in Gazli, Uzbekistan, where three earthquakes were recorded. These were attributed to the extraction of fossil fuels. Many experts agree to the link between hydrocarbon mining and seismic activity. This is especially true if the oil well is located along a region with active tectonic activity.
Super massive buildings
The current breed of large skyscrapers may not be big enough to create earthquakes. However, super massive buildings planned for the future could probably have enough weight to cause changes to rock formations inside the earth. Exactly how big the building should be to cause an earthquake has not been determined.