john's blog

Many apologies if you have come to the site in the last few hours and found it offline or not operational.  Our primary servers are in the northeast, a location we chose because we assumed it was safe from effects of earthquakes, wildfires, flooding and hurricanes (as Irene demonstrated last year).  But apparently not from storms of the century.  Who knew?  Please check back with us later today when full functionality should be restored.

If you are a regular visitor to this site, you can track the change in earthquake probability in regions such as southern California by the simple technique of taking screen shots and then comparing images from different dates.  Below I show two screen shots of forecast probabilities for two dates, 9/29/2012 and 10/29/2012.  I use the forecast for M>5 within 1 year from the date indicated.  Boxes show regions where the forecast has changed over 1 month's time from 9/29/2012 to 10/29/2012.

As a matter of interest, I ran an ANSS catalog search of the region surrounding yesterday's Haida Gwaii (Queen Charlotte Islands) earthquake.  It appears there were 4 M>5 foreshocks of the M7.7 event that occurred in the hours before the mainshock.  These events are listed below.  

Yesterday a magnitude M7.7 earthquake occurred at 8:04 pm local time on the Queen Charlotte Islands fault system near Haida Gwaii, Canada.  This event occurred near the junction of a series of spreading centers (mid ocean ridge) with the Queen Charlotte Islands strike slip plate boundary.  Historically, most of the earthquakes in this region have a sense of motion that is parallel to the plate boundary.  These are called "right lateral strike slip" earthquakes.  Yesterday's event actually had normal faulting mechanism, characteristic of local crustal tension. 

The ACES group has been meeting at various sites around the Pacific Rim since 1998.  Started by Professor Peter Mora from the University of Queensland, the organization was approved by the Industrial Science and Technology Working Group of APEC at the 1997 Singapore meeting.  The first meeting was held at UQ in Brisbane, AU, and Noosa Heads, on the Gold Coast. It was a memorable meeting with many of the worlds' leading seismologists in attendance. Details can be found at: http://quakes.earth.uq.edu.au/

The news on earthquakes was dominated today by the conviction of 7 Italian seismologists on charges of manslaughter for failing to adequately convey the risk of earthquakes during the April 6, 2009 L'Aquila earthquake sequence [1,2].  News stories characterize the reason for the conviction as failing to predict the magnitude 6.3 earthquake in which 308 persons perished.