‘The central United States is experiencing an unprecedented surge in earthquakes that began in 2009, rising from an average of 21 magnitude 3 and larger quakes to over 650 in 2014 alone. This increased earthquake activity is found in just a few concentrated regions around the country, with the lion’s share in Oklahoma. In 2014, there were more magnitude 3 and larger earthquakes in Oklahoma than there were in California. The increased earthquake activity is limited to areas of new and emerging oil and gas production and is undoubtedly caused by some of the techniques they use.

With a focus on oil and gas production and related techniques, I will discuss the many ways that humans can cause earthquakes. In the case of fluid injection, the primary source of the recent increase in earthquake rate, the fluid pressure increase from injection can be transferred many miles from the injection point. This fluid-pressure increase, in effect, lubricates the faults, making them more prone to slipping in earthquakes.’

Read more: Yes, humans really are causing earthquakes