Human activity is contributing to an increase in earthquakes, stated a recent report by the Human-Induced Earthquake Database (HiQuake), the world's most complete database of earthquake sequences proposed to have been triggered by human activity.

Published in the journal Seismological Research Letters, the report pointed out that 37% of induced earthquakes are related to mining projects. The second “most common cause” of induced earthquakes is water impounded behind dams, which makes up about 23%.

With some surprises, unconventional oil and gas extraction projects using hydraulic fracturing, are now a frequent addition.

"Any successful hydraulic fracturing operation induces microseismicity because the rock is fractured. The number of hydraulically fractured boreholes has increased in recent years, so there is obviously going to be a trend between the number of successfully hydraulically fractured boreholes and the amount of associated microseismicity," said Miles Wilson, a geophysicist at Durham University working on the HiQuake research effort.

Other human activities related to unconventional extraction are also reported causes of induced earthquakes in the study.

"The most obvious induced seismicity trend is the recent increase in the number of waste-fluid disposal projects reported to have induced earthquakes. This increase is consistent with increased waste-fluid disposal activities in the US," said Wilson.

In his opinion, human activities that act on the crust are likely to multiply in the future, as projects to tap into geothermal sources of energy and to store carbon dioxide emissions become more widespread.

"Additionally, mines may become larger, deeper, and more extensive, surface water reservoir impoundments more common, and buildings on larger scales could be built to meet a growing world population and resource demand," said Wilson. "Perhaps one day a balance will need to be struck between earthquake hazard and resource demand."‍