Oct. 3, 2017 - Not all earthquakes occur naturally. Some are man-made. Mining projects and water in dams are the two most commonly reported causes. A new study and database aims to track earthquakes proposed to have been triggered by human activity.
These are some of the biggest earthquakes that are thought to have been caused by human activity:
China: 2008 magnitude 7.9 Wenchuan earthquake. Likely caused by construction and filling of a nearby dam.
Nepal: 2015 magnitude 7.8 earthquake. Likely caused by groundwater extraction.
Oklahoma: 2016 magnitude 5.8 earthquake. Likely caused by fracking wastewater injection.
Click here to read How Humans Are Causing Deadly Earthquakes.