Any earthquake has a 5% chance of being a foreshock of a much larger earthquake.
USGS under the U.S. government Sally Jewell, the chief executive to lead the Interior Department, Ms. Jewell, a former oil company engineer and longtime advocate for conservation and outdoor recreation,...
earthquake chart
http://mbmgquake.mtech.edu/earthworm/wavef_disp/current/QLMT_EHZ_MB.2016082700.gif