NK NuKes
Posted: Tue Feb 12, 2013 5:56 am
North Korea is suspected of conducting a nuclear test, several nations say, after an earthquake that monitors said had "explosion-like" qualities.
A shallow 4.9 quake was detected at 11:57 (02:57 GMT), the USGS said.
Its epicentre was in the same location as the Punggye-ri underground nuclear test site, at which activity has been observed in recent weeks.
There has been no word yet from North Korea, but it announced plans for a third nuclear test last month.
The UN Security Council had warned of "significant consequences" if Pyongyang went ahead. It is to hold an emergency meeting at 14:00 GMT on Tuesday in New York, diplomats say.
North Korea is not prone to seismic activity. The USGS said the quake occurred at a depth of 1km (0.6 miles).
A UN monitoring agency described it as an "unusual seismic event" with "explosion-like characteristics".
"Its location is roughly congruent with the 2006 and 2009 DPRK [North Korea] nuclear tests,'' said Tibor Toth, executive secretary of the Comprehensive Nuclear Test Ban Treaty Organisation.
Japan's Meteorological Agency said the tremor was "different from a normal earthquake".
"We believe that there is a possibility that North Korea carried out a nuclear test, looking at past cases," said Chief Cabinet Secretary Yoshihide Suga.
A spokesman for South Korea's defence ministry echoed those sentiments, saying the reported magnitude equalled an estimated yield "of 6.0-7.0 kilotons".
If confirmed, this would appear to be bigger than past tests, reports the BBC's Lucy Williamson in Seoul.
South Korea has raised its military alert and outgoing President Lee Myung-bak convened a meeting of the National Security Council.
Japan's government is also holding an emergency meeting, public broadcaster NHK reported. Prime Minister Shinzo Abe said his government would "consider every possible way to address this issue".
North Korea's two previous nuclear tests were both conducted shortly after rocket launches condemned by the UN as disguised tests of long-range missile technology.
It announced in January that it planned to conduct a "high-level" nuclear test, in response to expanded UN sanctions imposed after its latest rocket launch on 12 December 2012.
That rocket launch successfully put a satellite into orbit, in an apparent breakthrough for the North.
There was no explanation of what "high-level" meant, but the reference led to speculation that the test would be of a uranium device. The two previous tests involved plutonium devices.
The US and North Korea's neighbours fear Pyongyang's ultimate goal is to put a nuclear warhead on a long-range missile that could target the west coast of the US, but it is not believed to have mastered the technology yet.
The US, South Korea and Japan had all warned Pyongyang not to go ahead with the test. China, North Korea's closest ally and biggest trading partner, had also called for restraint.
