Modern science is actively arguing that human activity extensively damages the environment. That results in climate change, global warming, and an increase in natural disasters. One of the underexplored disasters is the human impact on seismic activity. Gibbens (2017) suggests that people often perceive earthquakes as unforeseeable phenomena they cannot influence; however, findings demonstrate that 730 quakes during the past hundred and a half years were caused by human intervention. The technogenic impact on the geological environment has reached such a force that earthquakes provoked by human engineering activities have become possible. Due to technological progress, artificial earthquakes occur, and their number increases every year following the strengthening of destructive human impact on the planet. Therefore, it is crucial to identify and evaluate the direct human influence on seismic activity.
Essentially, the complications are caused by the fact that it is challenging to ensure that human activity can influence the movement of tectonic plates. In addition, it is crucial to determine the extent to which natural disasters appear by themselves. First, earthquakes are tremors and vibrations of the Earth’s surface caused by natural causes, mainly tectonic processes. Displacements in the interior generate seismic waves are vibrations that propagate in the Earth’s crust and subcrustal lithosphere. Without a doubt, earthquakes occur naturally because of tectonic shifts, oceanic unloading, erosion, and the natural groundwater movement (Foulger et al., 2018). In addition, earthquakes may also occur due to volcanic activity due to thermal convection; updrafts arise in places where the plates are moving apart, spewing lava. This process is accompanied by the release of energy and generates volcanic earthquakes.
Interestingly, earthquakes can be caused by human activity; induced seismicity refers to earthquakes wholly or partially caused by humans. In addition, the destructive power of natural earthquakes may increase due to human activity. One of the most crucial reasons that trigger earthquakes is material removal from the surface, which leads to collapses and fractures (Gibbens, 2017). Foulger et al. (2018) emphasize that human activity that disturbs the Earth’s crust may create seismicity. If earthquakes resulting from natural processes are mainly confined to active tectonic structures, then induced seismicity occurs in areas of active exploitation of the Earth’s interior by humans and is directly related to the economic activity conducted. Gibbens (2017) adds that researchers determined that induced earthquakes can reach high magnitudes. Notably, the number of induced earthquakes increases every year following the strengthening of the destructive effect of man on the Earth (Foulger et al., 2018). For instance, in flooded areas during the construction of large reservoirs, tectonic activity increases – the frequency of earthquakes and their magnitude grow significantly.
Seismologists note that tremors increase in the territories surrounding large reservoirs, natural resource extraction zones, existing and developing mines and quarries, and other engineering structures. Gibbens (2017) affirms that the deadliest earthquakes were caused by water reservoir impoundment and dam building. The frequent occurrence of underground processes in the area of reservoirs is because a significant mass of water presses on the Earth’s crust and erodes rocks. Moreover, the larger the reservoir, the higher the probability of an earthquake. Since, in addition to the mass of water, as an excess load in the upper part of the Earth’s crust, a vital role is played by rocks’ strength properties decrease due to the water penetration into them through cracks.
It should be noted that the rapid construction of reservoirs also contributes to earthquakes since the pore pressure in the rocks does not have time to respond to new conditions. Moreover, earthquakes were also presented by nuclear explosions in various locations and sites (Gibbens, 2017). As a result, significant human activities’ impact on seismicity is undoubtful.
Interestingly, both natural and induced earthquakes are impacted by stresses in geologic faults and fluid injection in deep disposal wells (Arbor, 2017). Arbor (2017) suggests that the stress drops of both types of earthquakes are identical when considering the earthquakes’ depth and faulting system. Thus, the GMPEs, namely ground motion prediction equations, can be applied to induced and natural earthquakes.
As recorded before, human activity can directly cause artificial earthquakes, with the number of such events increasing yearly because of destructive human actions. Artificial earthquakes, also known as induced seismicity, have been linked with many human interventions, especially in industrial sectors, such as mining, water pollution, oil and gas fracking, and many other detrimental activities. However, academics note that the issue’s presentation, especially by media and news outlets, is often unrestrained, restricted by a lack of scholarly expertise, or otherwise not entirely honest to the findings.
A literature review analyzed media attention towards induced seismicity concerning state policy and gas and oil fracking in Ohio, Oklahoma, and Texas. The research found that the exposure was either insufficient or went beyond the offered data (Fisk et al., 2017). The point has merit as it exposes inadequacies in which the public will perceive the impact of induced seismicity, whether the news outlet emphasizes or downplays the issue. In this particular case, the review argues that the induced seismicity origin of human impact is overstated. Researchers and academics may agree that insufficient or incorrect media intervention in induced seismicity is a drawback. Those within the oil and gas fracking industry may agree with this point of view.
However, despite the inadequate media intervention, the review also downplays the impact of human activity on induced seismic activity. Wang et al. (2017) highlight that induced earthquakes are hazardous to communities worldwide because of the ground motion. The consequences of anthropogenic earthquakes are similar to those of natural tremors, but they are most often observed previously in regions with little or no seismic activity. Most natural earthquakes occur along fault lines; however, induced earthquakes caused by human activity can occur far from the edges of tectonic plates (Gibbens, 2017). Wilson et al. (2017) present that 730 anthropogenic projects lead to earthquakes. According to Wilson et al. (2017), mining, fluid injection, and water reservoir impoundment are the most common human activities that may result in earthquakes. Adushkin (2016) claims that human activities, such as extended mining and production, cause solid tectonic earthquakes.
Wang et al. (2020) emphasize that human activity, for instance, injection, may result in seismicity. Consequently, seismicity may be induced instantly if the injection connects with significantly stressed faults through a fracture. Hence, “if the raised pressure does not spread to the background value,” the seismicity may remain for a few years after finishing the injection (Wang et al., 2020, p. 1). Zang et al. (2018) suggest that nowadays, expanding human interaction with the Earth’s surface catalyzes a significant magnification of earthquakes. The authors illustrate the causes, such as “injection rate, cumulative injected volume, wellhead pressure, injection depth, stress state, rock type, and proximity to faults,” that affect the probability of induced seismicity (Zang et al., 2018, p. 475). Therefore, the injection may be highly dangerous if not analyzed and done correctly.
In addition, it has been frequently cited that activities such as oil and gas fracking have a connection with artificial earthquakes, and this relation cannot be ignored. Current hydraulic fracking, which often occurs in the collection of gases and oil, has shown to have higher propensities of seismic events, an essential argument for the relevance of human impact of induced seismicity (Zang et al., 2019). Arbor (2017) states that, according to the U.S. Geological Survey, wastewater disposal in deep wells related to oil and gas extraction resulted in a dramatic growth in the number of earthquakes in the U.S.A. Gibbens (2017) ensures that people will unlikely stop the technological progress and development, which may cause tremors; however, people can analyze the data and prepare better to avoid negative consequences. Therefore, communities worldwide require precise “seismic hazard information, ground-motion hazard in particular, for developing mitigation strategies or policies” (Wang et al., 2017, p. 4). Foulger et al. (2018) claim that people should perceive industrial activity as a timescale modifying process to predict future consequences rather than earthquakes. Thus, the probability of earthquakes can be scaled, evaluated, and predicted.
To conclude, earthquakes can be caused by both natural causes and human intervention. Natural earthquakes occur anywhere on the Earth, where the accumulated elastic deformation energy is sufficient for the propagation of cracks along the plane of the fault. Although most earthquakes are caused by the movement of the Earth’s tectonic plates, human activities can also cause earthquakes. Activities above and below ground can change stresses and strains in the crust, including reservoirs’ construction, extracting natural resources, and pumping fluids underground for landfill or hydraulic fracturing. Oil and gas production, water from the Earth’s interior, and other human activities lead to a change in reservoir water pressure, which affects the redistribution of stresses, revitalization of movements along faults, and new cracks. It must be said that the problem of induced seismicity is very urgent these days, and much attention is paid to it both in applied and basic seismology.
The colossal growth of urban agglomerations, the withdrawal of oil, gas, and water from large fields, and the construction of high dams and huge reservoirs – all lead to an increase in seismic risk. The consequences of induced seismicity can disrupt pre-existing faults in the Earth’s crust and disturb the integrity of the tightness of storage sites. Thus, earthquakes may occur because of human impact, and the number of induced earthquakes is growing as people continue to influence the environment destructively. For a full-fledged seismic forecast, it is necessary to predict the place, time of earthquakes, and their strength. In all cases, the basic approach for avoiding the dire consequences of human activity is an assessment of the seismic hazard of the region. Therefore, to avoid caused earthquakes, it is important to predict, associated with a probabilistic assessment of the terrain, the general hazard of earthquakes, including the frequency and magnitude of destructive earthquakes in this area.
References
Adushkin, V. V. (2016). Tectonic earthquakes of anthropogenic origin. Izvestiya, Physics of the Solid Earth, 52(2), 173-194.
Arbor, A. (2017). Shake it up: Human-induced and natural earthquakes in the central U.S. are ‘inherently similar’. The University of Michigan. Web.
Fisk, J. M., Davis, C., & Cole, B. (2017). Who is at ‘Fault’? The media and the stories of induced seismicity. Politics & Policy, 45(1), 31-50. Web.
Foulger, G. R., Wilson, M. P., Gluyas, J. G., Julian, B. R., & Davies, R. J. (2018). Global review of human-induced earthquakes. Earth-Science Reviews, 178, 438-514.
Gibbens, S. (2017). How humans are causing deadly earthquakes. National Geographic. Web.
Wang, Z., Carpenter, N. S., Zhang, L., & Woolery, E. W. (2017). Assessing potential ground-motion hazards from induced earthquakes. Natural Hazards Review, 18(4), 04017018. Web.
Wang, Z., Lei, X., Ma, S., Wang, X., & Wan, Y. (2020). Induced earthquakes before and after cessation of long‐term injections in Rongchang gas field. Geophysical Research Letters. 47(22), 1-12. Web.
Wilson, M. P., Foulger, G. R., Gluyas, J. G., Davies, R. J., & Julian, B. R. (2017). HiQuake: The human‐induced earthquake database. Seismological Research Letters, 88(6), 1560–1565. Web.
Zang, A., Zimmerman, G., Hofmann, H., Stephansson, O., Min, K., & Kim, K. (2019). How to Reduce Fluid-Injection-Induced Seismicity. Rock Mechanics and Rock Engineering, 52, 475–493. Web.