Update on the Guatemala Earthquake

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As summarized below, the Guatemala earthquake of 11/7/2012 was a M7.4 event in which several tens of persons perished, with more injured.  It was followed several days later by a M6.5 aftershock.  Below we show a comparison of forecast contours for this event, comparing the pre-mainshock contours on 11/7/2012 with those from today, 11/14/2012. 

Unlike for other areas we have recently examined, the contours are little changed (red boxes show the only obvious change).  Recall that the contours are for probability of M>6.5 earthquakes over the next year.  Unlike other areas we have examined recently, there seems to be no recognizable earthquake "cycle" here.  Why might this be?

To find at least a partial answer, we consulted the ANSS earthquake catalog for events larger than M6.5, and for the region between latitudes 10 and 19 degrees north; for longitudes -96 and -84 degrees west; and for the last decade.  The results are shown in the table below the contour plots.  It can be seen that there have been 5 events having M>6.5 in this region over the past 3 months, 3 of these having magnitudes equal or larger than M7.4.  We speculate that this might imply more events of this size or larger in the region in the relatively near future, but at this point, all we have are the current data.