Today's M7.4 Aftershock

john's picture

This latest M7.4 quake(s) was centered 68 miles E of Sendai.  Apparently there may have been 2 of these M7.4 events 42 sec apart (according to the USGS data), although this may be revised to 1 such event (the event may have been double-listed).  A tsunami warning was just issued.

Referring to the blog post on March 17, it was computed that there was a 29% chance of an aftershock of magnitude M>6.7 within 12 months of that date and within 150 miles of Sendai. Tokyo had the second highest chance, 27%, at that time as well.  Again, this was within 150 miles of Tokyo and within 12 months of that date. 

Update April 7, 2011:  This event has now been recognized by the USGS to be a single event whose magnitude is better estimated as M7.1  There was no significant tsunami from the event.  3 persons were reported killed and approximately 1 million homes are without power for now.

Risk Alert