If you are interested in Earthquakes I highly recommend this site;
earthquake.usgs.gov...
Also this one; neic.usgs.gov...
And Lastly; neic.usgs.gov...
Many recent earthquakes may have been the aftershocks of large quakes that occurred hundreds of years ago, according to scientists.
In the journal Nature, researchers described a new pattern in the frequency of aftershocks that could explain some major quakes.
They found that, away from plate boundaries, echoes of past earthquakes can continue for several hundred years.

