North Korea conducts third nuclear test in DPRK history

Photo from North Korea's official Korean Central News Agency (KCNA) on December 12, 2012 shows North Korean leader Kim Jong-Un giving final orders for the launch of the Unha-3 rocket, carrying the satellite Kwangmyongsong-3, at the general satellite control and command center in Pyongyang.

UPDATE: North Korea confirms a nuclear test was conducted today. From KCNA, the state news agency:

It was confirmed that the nuclear test that was carried out at a high level in a safe and perfect manner using a miniaturized and lighter nuclear device with greater explosive force than previously did not pose any negative impact on the surrounding ecological environment.

"Amid talk of a possible nuclear bomb test, North Korea vowed Tuesday to carry out a 'high-intensity, all-out action," CNN reported earlier today.

They just made good on that threat.

Voice of America Northeast Asia bureau chief Steve Herman tweeted just now that "Seismic activity [has just been] detected in #DPRK… believed to be "man-made" per various #ROK sources… Speculation now that #DPRK may have conducted a nuclear test."

Here's a first briefing from the Associated Press, and another from CNN. The government of South Korea estimates the intensity of what would be North Korea's third known nuclear test at 6 to 7 kilotons, though it's too early to independently confirm.

Here is the USGS event data.

A quick Google Maps zoom-in on the coordinates shown in that USGS link reveals that the "earthquake" took place near "Nuclear Test Road."

Sinocism reporter Bill Bishop points to a seismic reading from China showing a 4.9 quake at 10:57am local time, and word that an "explosion" is suspected.

Here's the official seismic data from the PRC, indicating a "suspected explosive."

The area in which the event occurred has little or no history of natural seismic activity.

We don't know yet whether the bomb was plutonium-based (as past tests were), or uranium-based. Here's why uranium would be even more worrisome.