OKANOGAN, Wash. — A 3.0 magnitude earthquake struck early Wednesday morning near Okanogan.

Geologist Robert Yeats, author of 'Earthquake Time Bombs', has highlighted the risks associated with the presence of several large US cities in the Pacific Northwest's Cascadia subduction zone.

Subduction zones are the most important sites of material exchange between the crust and mantle on Earth. They are also the locations where the largest deposits of strategic metals, such as copper, ...