On Sunday, September 11, 2016 at about 1pm an earth tremor rocked the Jaba community of the Kwoi area of Kaduna state. On Monday, September 12, 2016, the earth tremor reoccurred, throwing residents into panic. When the tremors started, a journalist in the Kwoi area reported: ”Though some people didn’t begin to flee the city, big intensity is noticeable there. The earth vibrates under legs of people. It began with morning and if it proceeds till the evening, people will have no choice. They should leave the city and to go to safer places.” Another witness, Hon Badugu Nehemiah said: “Since morning, many people in our villages ran because buildings and the earth shivered. Many churches shall reduce the programs of Sunday service because of earthquake threat. The earth is still shaking.”
Experts feel that the tremors were not as a result of natural causes. There are a couple of man-made activities that could have given rise to the tremors.
Here are some of them:
1. Gurara Dam
Gurara Dam, Kaduna state
One reason behind the tremor, might be the Gurara dam in Kaduna state. Water is heavier than air, so when the valley behind a dam is filled, the crust underneath the water experiences a massive change in stress load. For example, the Hoover Dam area in the US, experienced hundreds of quakes as Lake Mead filled. University of Alaska seismologist Larry Gedney explained, “Since the dam reached its peak of 475 feet in 1939, the level of seismicity has fluctuated in direct response to water level.” Other examples of dam-caused quakes abound and research indicates that about one-third of human-caused earthquakes came from reservoir construction. This science shows that the Gurara dam might be the reaon behind Sunday’s tremor.
Gold mining in Nigeria
Mining is also one of the likely causes of the earthquake. Mining leads to huge change in the mass of a region, and huge mass changes leads to change in the earthquake stresses of an area, sometimes increasing the chance of an earthquake and other times lowering it. In May, 2016, the Kaduna state commissioner for environment and natural resources, Hon. Shehu Balarabe, said that they will soon commence mining exploration. He said a recent survey indicated that Kaduna state is blessed with eleven minerals deposits with high prospects cut across the 23 local government in the state. “The Gold was discovered since 1991 in Birnin gwari,” the commissioner said adding, “We have N100 million to start the mining exploration in order to actually know the gold deposit in Birning Gwari. “The mining exploration will provide massive employment to our teaming Youth to make them self reliant which will even enhance security in our State,” the commissioner added. The mining activities in the state is also one of the likely causes of the tremors.
3. Fluid Injection
Another likely cause is the injecting of fluid underground. Science has proven that this can induce earthquakes, a fact that was established decades ago by USGS scientists. Fluid injection increases the fluid pressure within fault zones, essentially loosening the fault zones and making them more likely to fail in an earthquake. When injected with fluids, even faults that have not moved in historical times can be made to slip and cause an earthquake if conditions underground are appropriate. There are several purposes for injecting fluid underground. The three main reasons are wastewater injection, hydraulic fracturing and enhanced oil recovery. Within Kaduna state there haven’t been any reports of fluid injection recently. Yet, drilling activities due to mining might have led to injection of fluid.