The United States geological survey has reported this year that 7 million people live in places with unstable terrain in their hazard maps, whereby such places are prone to induced tremors. These places include: Texas, Colorado, New Mexico, Oklahoma, Kansas, Alabama and Arkansas.
When some the below human activities are carried out in such places, earthquakes may occur. Such human activities include:
- Building of a dam
When a dam is being dug, the valley behind it is usually filled with mass of debris obtained in the process. This leads to increased stress on the crust beneath and since the weight of water is higher than that of air, the load on the crust increases and this triggers earthquake.
A lot of researches indicate that a third of the man-made earthquakes result from dam construction. In the year 2008, the scientist raised a claim that the earthquake that occurred in China at that time might have been caused by the construction of 3 dams, although there was no absolute evidence.
- Construction of very large buildings
The larger the building, the higher the weight of that building. Some of the largest buildings in the world have been suspected to be a cause of man-made earthquakes due to the weight they apply on the earth’s crust. For example, in the year 2005 a geologist claimed that the tallest building then, that is the Taipei 101, was triggering earthquakes in a fault in Taiwan.
- Increased coal extraction
This was mostly practiced in the United States because coal was used as a source of energy by more than 50% of the population mostly from the year 2008.There were many coal mines. Generally, Coal mining leads to change in mass of a given region because during coal extraction, water is also extracted and this leads to either increase in earthquakes increase or reduction. Dr, Christian Klose of Columbia University suggests that most of the human-caused earthquakes in 2006 were caused by mining operations.
- Oil and gas extraction
The effect in this is the wastewater disposal wells in the oil and gas firms. When the fluids are pumped into the deep wells, they put a lot of pressure on the faults instead of lubricating them and thus driving the walls apart. This leads to relief of stockpiled tectonic pressure in form of an earthquake.
EFFECTS OF EARTHQUAKES
Economical effect. Recently, the U.S geological survey released information on human-made earthquakes triggered by wastewater injection linked with the oil and gas extraction. Earthquake insurance will continue to hike in the zones affected by the induced seismicity due to the increased likelihood of destruction of property by earthquakes in such areas. This information may affect both the small and large business firms.
Earthquakes threaten human life. Earthquakes may lead to deaths and loss of property. This has mostly experienced in the earthquake prone areas. This has claimed the life of both young and old.
Earthquakes do great damage to buildings, railways, dams, pipelines and many other structures. Earthquakes can also trigger landslides, mudflows and also cause alteration in the groundwater flow.