Can we determine the NK nuclear detonation strength?

mkarger

News reports have it at 4.9 magnitude and a depth of 1 kilometer

The USGS appears to have it at 5.1 and the depth is not currently known accurately.

http://earthquake.usgs.gov/earthquak...t0.php#details

http://abcnews.go.com/International/...ry?id=18444191

Borek

I asked similar question back in nineties, when French did their last nuclear test. The short answer I got - from some seismologist - was "no". Too many variables.

I suppose some rough estimates on minimum and maximum value are possible. Wikipedia page on Richter scale gives something in the range of 0.5kT as an equivalent (in terms of amount of energy) of 5.0. But it is not even clear to me if the magnitude given is on the Richter scale, plus it is unlikely that all energy was used to shake the ground, so I doubt it is even a reasonable low estimate.