While earthquakes are often thought of as unpredictable forces of nature, this isn’t always the case and man is becoming more responsible for creating earthquakes than ever before.
According to The Human-Induced Earthquake Database, there have been 1174 projects with reported induced seismicity at the time of writing this article. You can download the Excel sheets from their website. Also listed are the causes and their percentages which break this number down as:
- Fracking – 33%
- Mining – 25%
- Water Reservoir Impoundment – 16%
- Conventional Oil and Gas – 11%
- Geothermal – 6%
- Waste Fluid Disposal – 4%
- Nuclear Explosions – 2%
- Research – 1%
- Unspecified Oil and Gas/Waste Fluid Disposal – 1%
- Groundwater Extraction – 0.6%
- Deep Penetrating Bombs – 0.3%
- Construction – 0.2%
- Carbon Capture and Storage Schemes (CCS) – 0.2%
- Coal Bed Methane (CBM) – 0.1%
- Chemical Explosions – 0.1%
As you can see from the list above, fracking and mining are the leading causes which are to be expected due to the fracturing of the rocks. Most of the maximum observed earthquakes seem to fall between a magnitude of 3 and 4 and as I am looking over the data, it seems that the largest induced earthquake happened in 2008 in China which had a magnitude of 7.9. This was caused by the impoundment of the Zipingpu Reservoir only a few kilometers away from the mainshock epicenter. Some 80,000 people lost their lives or went missing.
While these earthquakes are not caused by nature, they still have the potential to be just as dangerous and deadly.
Fracking can induce seismic activity, both directly and from disposing of wastewater used in the process—the byproduct of water, sand, and chemicals used to hydraulically fracture hydrocarbons from the rock. That high-pressure wastewater can crack rocks and lubricate faults.
In terms of mining, mines are getting both bigger and deeper which is raising the risk of causing a human-induced earthquake. To make these mines to the required sizes, they need to remove more and more material from the earth which causes instability that can lead to sudden collapses that trigger earthquakes.
It is only a matter of time until a human-induced earthquake leads to another massive loss of life such as that in China. The fact is, we will never stop digging into the earth or injecting wastewater which is why we must remain prepared.