Explore how North America is changing as its deep cratonic root thins and pieces are dripping into the Earth's mantle.

KTLA California Interactive Earthquake Map So far, there have been no reports ... according to the USGS. In North America, only Alaska records more quakes per year than California.

Additional information collected about the earthquake may also prompt U.S.G.S. scientists to update the shake-severity map. An aftershock is usually a smaller earthquake that follows a larger one ...

The North American and Pacific tectonic plates had moved past each other by more than 15 feet — compared to an annual average of two inches. The earthquake is estimated to have measured 8.3 on ...