Frackquake. It’s a portmanteau word that sounds like a superhero nemesis, but refers to a very real geological phenomenon. These are small earthquakes caused by hydraulic fracturing.
On the surface, this makes sense. Drilling equipment and high-pressure pumps generate vibrations. Seismographs can detect them. But geologists aren’t worried about the noise from the machine itself. They focus on what happens after the well is drilled.
The real danger lies in wastewater.
It’s not just dirty water. It is a mixture of spent fracturing fluids and various chemicals extracted from deep underground. Instead of treating the toxic sludge, energy companies often pump it underground. Specifically, it pumps fuel into already developed oil and gas fields, the same rock formations that produced the oil in the first place.
Why are they doing this? It is cheaper and easier than surface treatment.
However, this practice changes the delicate pressure balance between rock layers. Think of the Earth’s crust as a bundle of plates. When a large amount of fluid is injected, the pore pressure increases. This pressure can lubricate faults in rock formations.
Injecting wastewater into areas where oil or gas has been extracted can change the pressure balance between rock formations and lubricate faults within the rock formations.
Once the fault is lubricated, it slipss. The result is an earthquake.
This is usually not a catastrophic event. Most induced earthquakes are too small for humans to detect. These are only registered for sensitive devices. However, the possibility of a larger earthquake still exists. Lubrication reduces friction and suddenly releases structural stresses.
We usually think of earthquakes as natural phenomena. Purely destructive. But when we pump millions of gallons of liquid back underground, we become part of the system. Change the pressure. We change the friction. We cause vibrations.
It’s not a question of whether it will happen. This is the pressure that the local geology can withstand before it slipss. If you slip once, it will be damaged.
