Mitigation of Human-made Earthquakes in Tangshan

Coal extraction through surface mining which utilizes blasting in Tangshan makes the rock weak and this causes the fault lines along which rock breaks leading to an earthquake. To mitigate this, geoengineering operations such as mining and seismic events are analyzed using statistical, physics-based and source mechanisms models. Furthermore, the construction of dams causes underground rocks to freeze and thaw due to pressure as tectonics constantly move. To mitigate this, the design of tailing dams to take into account the horizontal accelerations associated with seismic activity.

Section 2:

Describe the current mitigation plans details and outcome for your impact/hazard.

The models adopted by geoengineering operations in mining sites discriminate between human-caused and natural seismic activity. In addition, hazard mapping in time and space is critically done to provide information to authorities concerned with mining activities and therefore reduce the associated hazards that cause earthquakes in Tangshan.

Describe what you believe were shortcomings of the plan.

Earthquake hazard is not taken into account in the mineral processing stages of coal extraction apart from blasting. Additionally, it is generally critical to model the seismic events for post-processing. As a result, these models have been crucial to understanding the risks associated with human-made earthquakes rather than addressing it. Ensuring sustainable practices is especially important in the regions of high population densities to prevent catastrophes.

Section 3:

Describe your proposed mitigation plan to replace the current plan.

My proposed plan is the installation of seismic monitoring systems and microseismic monitoring systems as an earthquake early prevention system that aims to look at the environment around the mining facility and the dams.

Describe why you believe your mitigation plan is an improvement.

An earthquake early warning system detects P-wave which is a more rapid seismic wave. Furthermore, it exceeds certain parameters and then determines instantly an accompanied S-wave that is a much more damaging vibration and travels less rapidly. Microseismic monitoring systems pick up levels of energy that are much smaller and listens to the event around mining operation. Furthermore, they give warnings of increased activity that may lead to catastrophic rock burst in dams and around mining operations. The natural release of strain energy caused by slippage on the faults would be picked up around the disturbed zone in a drift which is in effect tiny rock bursts that do not cause damage. When impeded and the strain levels build up, they release a significant amount of energy which are the damaging rock bursts that close a drift.

Add an illustration or data that supports your reasoning.

S-waves and P-waves tomography of Japan subduction zone (Liu and Zhao 4)

Microseismic monitoring in Japan (Liu and Zhao 10)

Section 4:

Describe the intended audience for your mitigation plan proposal.

The intended audience is the geoengineering operations team, civil engineering excavation team around the mining operation, and construction team in dams.

Describe how you might gain approval to implement your plan

To gain approval a detail presentation and report would be presented to the team for thorough scrutiny. Additionally, the population of Tangshan fends from working in coal mines around the mining regions, therefore, the mitigation plan proposal presented to the department of human welfare will be of great interest as an oversight for the implementation.

Reference

Liu, Xin and Dapeng Zhao. “P and S Wave Tomography of Japan Subduction Zone from Joint Inversions of Local and Teleseismic Travel Times and Surface Wave Data.” Elsevier 252.1 (2016): 1-22.