Surface Water - clean water for all

Scientists are uncovering a hidden and surprisingly complex earthquake zone beneath Northern California by tracking swarms of tiny earthquakes that are far too weak to feel. These faint tremors are revealing what lies beneath the surface where the San Andreas fault meets the Cascadia subduction zone, one of the most dangerous seismic regions in North America.

Source: https://www.sciencedaily.com/releases/2 ... 053529.htm