The Washington Post reports that the U. S. has detected signs of a nuclear detonation in the air over North Korea:
Initial environmental samples collected by a U.S. military aircraft detected signs of radiation over the Sea of Japan, possibly confirming North Korea’s nuclear test, intelligence officials said yesterday.
Officials said the positive radiation result was consistent with an atomic test and would make it possible to rule out the possibility that Monday’s test had been conducted with conventional explosives alone. But intelligence and administration officials were cautious about reaching a conclusion before reviewing all incoming data. “The intelligence community continues to analyze the data,” said Frederick Jones, spokesman for the National Security Council. “When the intelligence community has a determination to present, we will make that public.”
Earlier detection attempts by the United States, China and South Korea did not pick up any radiation. An intelligence official said additional samples are being collected, and analysts are also taking a harder look at seismic data, satellite photos and communications intercepts.
North Korea, according to U.S. intelligence estimates, has enough plutonium for as many as a dozen nuclear weapons, depending on their level of sophistication. Some analysts have judged Pyongyang’s technical capabilities in the nuclear design field to be at a low level. But there are now discussions among top U.S. weapons scientists and analysts whether North Korea may have managed to test a miniaturized warhead or a more sophisticated design than was expected.
There’s no way of knowing, of course, whether this report is legit or an attempt to keep the ball up in the air. But it’s another data point.
Previous post on the subject:
Dave,
The only detectable radioactive signature from a properlly stemmed test like this will probably come from isotopes of noble gasses like Argon and Xenon, which have the ability to pass throug faults in the earth relatively easily. I’d be very surprised if any particulate matter was detected from such a small (probably fizzle) test.
I’m not completely familiar with the science, but as the remnants of the fissioned material decays over the next several months, it may be possible to detect and collect additional evidence.