Here We Go Again?

-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”:

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”: Why?

Update: “Martin Kalinowski”: 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”: via the “International Seismological Centre’s Online Bulletin”: 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”: of a ~4kt test for weaponization.

Andreas says it took place at a “second test site”:, not far from the first.

One thought on “Here We Go Again?

  1. Allen Thomson

    I checked the official Ministry of Defense announcement to be sure there wasn’t some sort of translation glitch. There wasn’t:

    25.05.2009 года
    Сообщение Управления пресс-службы и информации МО РФ

    25 мая 2009 года в 4 часа 54 минуты 41 секунду по московскому времени Службой специального контроля Министерства обороны Российской Федерации на территории КНДР, в 80 километрах северо-западнее города Килчжу, зарегистрирован подземный ядерный взрыв мощностью от 10 до 20 килотонн.

    В настоящее время Служба специального контроля МО РФ продолжает мониторинг развития ситуации в режиме реального времени.

    “от 10 до 20 килотонн” is indeed and exactly “from 10 (up) to 20 kilotons.”


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