Invisible changes under the hood at the PNSN

Invisible changes under the hood at the PNSN

December 5, 2011

by John Vidale

  Just as you might move to new house, spending months picking it out and moving everything, we just switched to new software to drive our earthquake information.

We phased out XPED, written originally only for the University of Washington 20 years ago for slow black and white computers.  We brought in AQMS, the new national standard, which used color GUIs (graphical user interfaces) and has hundreds of options.  We are the second region after California to bring AQMS on line.  Hawaii, Utah, and the Central US will soon follow. Correction: We are the third region after California to bring AQMS on line, Hawaii has been using it for a while already.

For the past few months we ran both systems together to make sure the answers were right.  For example, the measurements of magnitude were done differently.  The plot below shows even two correct methods can disagree by up to 1 magnitude unit for the smallest events (ignore those events for which one magnitude is zero).


It's a relief to return to running just a single system.  When everything is working, fairly accurate info can be posted as fast as we can look at a couple of plots on our iPhones, so you can benefit as well.  You can check the earthquake map now on your smartphone, at this link.

Feel free to pitch in comments, should anyone have noticed this blog yet.  It's hard to home in on the hottest topics without hearing whether more or less details, jargon, figures, links, or verbiage is wanted.