Update:
Seismographic data from September 9th, the day the "bomb" went off.
Note that this following seismograph has a small jump at the same time as the one above, approximately 8:10 in Pyongyang and 16:10 in Universal Time
http://photon.physics.hmc.edu/research/geo/day3_4.gif
This was plotted in Canada, at the same time as the others.
http://]http://www.seismo.nrcan.gc.c...0912150000.gif