week3(下1)-North Korea nuclear:hydrogen bomb test

North Korea nuclear: State claims first hydrogen bomb test

6 January 2016

North Korea says it has successfully carried out its first underground test of a hydrogen bomb - a more powerful weapon than an atomic bomb.
If true it would be its fourth nuclear test since 2006 and mark a huge advance in its nuclear capabilities.
The announcement was swiftly criticised by world leaders with South Korea calling it "a grave provocation to our national security".
But there has been no independent confirmation of the North's claim yet.

Can North Korea now launch a nuclear missile?

Despite North Korea's claims, experts are sceptical that North Korea can make a nuclear weapon small enough to fit on a missile.

What do we know about the latest test?

Observers agree a nuclear explosion of some kind took place and it seems to have been a bit bigger than the last test in 2013, but not nearly big enough to be a full thermonuclear explosion - an "H-bomb" - as Pyongyang claims.

Why can't the world stop them?

North Korea has a determination to defy both world opinion and heavy sanctions to reach their nuclear goal. Crucially, its main ally, China, has proved either unwilling or unable to help.

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Suspicion an underground test had been carried out was first raised after the US Geological Survey detected unusual seismic activity at 10:00 Pyongyang time (01:30 GMT) - in the north-east of the country,

A 5.1 magnitude tremor was detected about 50km (30 miles) from Kilju city, near the Punggye-ri nuclear site, which monitors said was likely not natural.

Hours later, in a surprise announcement, a newsreader on North Korean state TV said: "The republic's first hydrogen bomb test has been successfully performed at 10:00 am on January 6, 2016."

North Korean leader Kim Jong-un had said last month that Pyongyang had developed a hydrogen bomb, although many experts were sceptical.

It could be days or weeks before independent tests are able to verify or dismiss the recent claim.

Hours before the seismic activity, South Korean media reported that Pyongyang had test-fired a ballistic missile from a submarine in late December. It is unclear whether the test was successful or not.

North Korea said in May it had conducted a similar successful submarine launch.

http://www.bbc.com/news/world-asia-35240012

Structure of the Lead：

WHO-  North Korea

WHEN-2016

WHAT-North Korea carried out its first underground test of a hydrogen bomb

WHY-North Korea has a determination to defy both world opinion and heavy sanctions to reach their nuclear goal. 

HOW-launch a underground test of a hydrogen bomb

Keywords：

1.hydrogen：氫

2. carry out ：實施
3.swiftly ：很快地

4.provocation：挑釁

5.confirmation：確認

6. thermonuclear：熱核　
7. defy：違抗

8. sanction：制裁
9.seismic：地震

10.tremor：震
11.verify：校驗
12. magnitude：大小
13. submarine：潛艇