-It’s too early to say. But at first glance,- it’s already starting to look like Russia vs. the rest on the yield of “North Korea’s second nuclear test”:http://www.nytimes.com/2009/05/26/world/asia/26nuke.html:
Kim Sung-han, a security expert at Korea University in Seoul, estimated the test had a power of one kiloton of explosives, slightly more than the 0.8 kiloton detonation reported in 2006. If correct, that would be a fraction of the size of the blasts from American bombs that destroyed the Japanese cities of Hiroshima and Nagasaki in August, 1945 — themselves considered small by current standards.
But Alexander Drobyshevsky, a Russian Defense Ministry spokesman, told RIA-Novosti news agency offered a different estimate, saying that the force of the blast was 10 to 20 kilotons.
We’ve “been here before”:http://www.totalwonkerr.net/1971/russia-eyes-north-korea. Why?
Update: “Martin Kalinowski”:http://www.totalwonkerr.net/file_download/22/Kalinowski.pdf of Universität Hamburg has a higher estimate than does Kim Sung-han, but he’s still well south of the numbers given by the Russian Ministry of Defense:
bq. Several seismic observatories all over the world recorded an event that took place in the North East of the country. The U.S. Geological Survey determined the event time as 00:54:43 UTC. The location is close to the first nuclear test. The seismic body wave magnitude of 4.7 is larger as compared to the value of 4.1±0.1 in 2006. According to the assessment of Martin Kalinowski, this corresponds to an explosive yield of about 3 to 8 kilotons TNT equivalent with a most likely yield of 4 kt TNT. In 2006 the yield was unexpectedly low with an estimate of 0.5 to 0.8 kt TNT.
I’ll add more as it pops up, time permitting.
Later update: As usual, all the action is at ACW. Jeff has located “three estimates”:http://www.armscontrolwonk.com/2310/north-korean-nuclear-test-mb via the “International Seismological Centre’s Online Bulletin”:http://snipr.com/iqcx1. They cluster around 2 to 6 kt. Notably, the result from the Geophysical Survey of the Russian Academy of Sciences is basically in line with the others, and *not* with the announcement of the Ministry of Defense, which appears to float free of all observed data.
For whatever it’s worth, Kim Sung-han’s estimate — as reported in the NY Times and cited above — is also an outlier, but in the other direction.
Geoff has some thoughts about the “potential implications”:http://www.armscontrolwonk.com/2311/north-koreas-design-choices of a ~4kt test for weaponization.
Andreas says it took place at a “second test site”:http://www.armscontrolwonk.com/2312/greetings-from-geneva-more-on-mb-to-yield, not far from the first.