A study published in the journal Seismological Research Letters this week identified 730 sites where human activity caused earthquakes over the past 150 years. And while we've long known that people can influence seismic activity, researchers were surprised to find that human activity has induced earthquakes with magnitudes as high as 7.9—and that the number of earthquakes is clearly rising in some regions of the world.

Just like earthquakes caused by nature, human-induced earthquakes have the potential to be dangerous, even deadly. And geologists are only just beginning to understand the repercussions these quakes could have on people and the environment.

Here's what we know:

The effects of human-induced earthquakes may be similar to those created by nature, but are often seen