A team led by researchers at the University of California, Berkeley, has developed a new technique to distinguish between earthquakes caused by natural processes, such as the movement of tectonic plates, and those caused by human activities, such as fracking.

The technique, described in a paper published in the journal Science, uses data from seismic waves to identify the characteristics of the source of the earthquake.

- Natural earthquakes occur when rocks break under stress, releasing seismic energy.

- Human-induced earthquakes, on the other hand, are caused by activities such as fracking, which involves injecting fluid into the ground to fracture rocks and release oil or gas, or the construction of dams and reservoirs.

The researchers found that natural earthquakes have a characteristic "slow slip" phase, during which the rocks break slowly before the main rupture, whereas human-induced earthquakes lack this slow slip phase. This difference can be detected by analyzing the high-frequency components of the seismic waves.

The researchers tested the technique using data from 226 earthquakes, including 115 natural earthquakes and 111 human-induced earthquakes. They found that the technique was able to correctly identify the type of earthquake with an accuracy of over 90%.

This new technique has the potential to help scientists better understand the causes of earthquakes and to develop more effective ways to mitigate their effects. It can also help regulators to make more informed decisions about activities that could potentially trigger earthquakes.