There is a lot of speculation right now that the nuclear weapon North Korea claims to have detonated may have been a dud. It's a little early to go down that road, I think. There are some presumptions about what Kim was trying to accomplish that could be flawed. He might not have been trying for a city buster but for a smaller, sub-kiloton weapon. We don't know what he intended or any particulars of the design. Analysts are giving different answers all over the place right now.
Thesaid it had detected a 4.2 magnitude quake in North Korea at 10:35 local time (0135 GMT) on Monday, confirming a similar report from .
Gary Gibson, senior seismologist at Australia's Seismology Research Center, said a 4.2 magnitude quake would be the result of a one kiloton explosion.
"It depends on how the thing is set off. There is not a perfect correlation between magnitude and the yield and depends to some extent on the rock type they set it off in," he said.
"It is a relatively small nuclear test."
A U.S. intelligence source agreed that a preliminary examination of the data did not indicate a large blast or a series of explosions. But the source stressed that analysts were still working toward a definitive evaluation.
"It's premature because they're still evaluating the data," the source said.
The RIA news agency quoted on Monday Russian Defense Minister Sergei Ivanov as saying that the nuclear device tested by North Korea ranged between five and 15 kilotons.
The nuclear weapon the United States exploded over Hiroshima in 1945 produced a 12.5-kiloton yield.
In 1998, India carried out five underground nuclear tests at Pokharan in the western desert state of Rajasthan and declared itself a nuclear weapons state.
The total yield of the first round of blasts measured near 60 kilotons. Two days later, it exploded sub-kiloton devices that scientists said made it capable of conducting computer tests not covered by the Comprehensive Test Ban Treaty.
"Our biggest one was in the vicinity of 45 kilotons. That was thermo-nuclear," said S.K. Malhotra, head of the public awareness division of the Department of Atomic Energy.
Nuclear analyst Andrew Davies, from the Australian Strategic Policy Institute, said if the North Korean test yield was only a kiloton, Pyongyang may be disappointed.
"A kiloton is a very low yield and would tend to suggest, I would have thought, that the device was not all they hoped it would be," Davies told Reuters.
"If a nuclear, plutonium bomb fizzles, you can still get one or two kilotons quite easily. You still get a significant energy release. But an efficient device will give you more like 20 (kilotons)."
There is one highly troubling but unconfirmed report that the test was of a neutron bomb.
A source in Beijing who is close to the North Korean regime said Pyongyang had detonated a neutron bomb, designed to release larger amounts of deadly radiation than other nuclear weapons. There was no immediate confirmation of the claim.
That would be a bad thing. Worse than a lot of other scenarios. It's a bit to early to declare it a failed test, I think.
UPDATE: The Real Ugly American asks a few pertinent questions.
UPDATE: Donald Sensing is thinking along the same lines.