A small earthquake or tremor that occurs following a major one
[DOC] [TLE] aftershock | geology | Britannica.com [PAR] Any of several lower-magnitude earthquakes that follow the main shock of a 
larger ... Small tremors that follow an earthquake are considered aftershocks if 
they ... Small aftershocks occur with a greater frequency than large ones; 
however, ... Usually, a major or even moderate earthquake of shallow focus is 
followed by many... [DOC] [TLE] We're all living in the global aftershock zone | EARTH Magazine [PAR] Can one earthquake trigger another hundreds or even thousands of ... of tremors, 
microquakes and small temblors all over western North America, ...