Some scientists have traced the increase in earthquakes to human activities, especially in areas not known for the presence of fault lines or past seismic (地震的) activity. The idea of humans causing earthquakes may seem strange at first. After all, you can run around your backyard and jump up and down as you want, and the ground isn't going to start shaking. However, scientists have identified a variety of large scale human activities that can result in earthquakes.
Scientists have confirmed over 700 places where human activities have caused earthquakes over the last century. While many human-related earthquakes are small and don't cause much damage, some of them can be serious and dangerous. In fact, scientists believe human activities have caused earthquakes with magnitudes as high as 7. 9 on the Richter scale.
Scientists believe that most human-related earthquakes are the result of mining. As companies drill deeper and deeper below the earth's surface to get natural resources, holes left behind usually cause instability (不稳固) which leads to earthquakes. Another human activity leading to earthquakes is fracking (水力压裂) for oil and gas, including the high pressure waste water processing that usually goes with fracking. In this process, water, sand and chemicals are pressed underground under high pressure to break rocks to release natural resources.
Building large dams can also cause earthquakes. Many people died as a result of a big earthquake caused by millions of tons of water that had been collected in a reservoir after a large dam was built over a known fault line.
These are not the only human activities that can result in earthquakes, though. Scientists point out that earthquakes can also be caused by other human activities, such as construction of skyscrapers and nuclear explosions.
There is no doubt that human activities have contributed a lot to social and economic development, but for our own benefit, we humans had better not push nature too hard, or we will have to pay a price.
