Today's M7.4 Aftershock
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.
About OpenHazards Bloggers
Steven Ward is a Research Geophysicist at the Institute of Geophysics and Planetary Physics, UC Santa Cruz. He specializes in the quantification and simulation of natural hazards. Read Steve's blog.
John Rundle is a Distinguished Professor of Physics and Geology at UC Davis and the Executive Director of the APEC Collaboration for Earthquake Simulations. He chaired the Board of Advisors for the Southern California Earthquake Center from 1994 to 1996. Read John's blog.