Changes in Forecast Contours for the British Columbia Earthquake

john's picture

I made some screen shots from the earthquake viewer page from before the BC earthquake, and compared it to a screen shot taken today.  The pre-earthquake shot was made on 10/28/2012, but before the ANSS catalog had updated with the earthquake and its aftershocks.  The results are shown in the first figure below. 

The global forecast contours are for a M>6.5 earthquake within 1 year.  Since the mainshock had a mag M=7.7, we would expect that an event of M>6.5 should occur as an aftershock.  In fact the seismological Baths' law would suggest that the largest aftershock should be about 6.5 or so.  Note that we have had one aftershock of M=6.2 so far.  The aftershock occurred in the region that is now blue, but was blank before, as shown in the second figure below.