Fluid injection triggers earthquakes indirectly, study finds

Artificially induced tremors start with slow, smooth slipping

induced earthquake

SHAKE UP  Researchers triggered and carefully monitored earthquakes along a fault beneath an underground research facility in southeastern France. The fault slid smoothly at first before sparking quakes, the researchers found.

Yves Guglielmi

The first up-close look at artificially triggered tremors suggests seismicity caused by human activities starts slow before shaking things up.