The Comprehensive Test Ban Treaty Organization, which monitors the globe for nuclear tests, said that its monitoring system had gone off-scale. The U.S. Geological Survey recorded a 6.3-magnitude earthquake, which was human-made. That's far larger than the seismic signature from the North's last test, conducted roughly a year ago. Here's what you need to know.
This was probably not an "ordinary" nuclear test
North Korea's previous nuclear tests have been in the tens of kilotons range. That corresponds roughly to a weapon the size of the ones used on Hiroshima and Nagasaki at the end of World War II. It's believed that the North's earlier tests were of nuclear weapons that use uranium or plutonium (or both) for their explosive yield.
This time, the North claims to have mastered a far more powerful hydrogen weapon. Some early estimates are putting this test in the hundreds of kiloton range.
#NorthKorea Range of yield estimates (50 to 1000+ kt) unusually high.— Bruno Tertrais (@BrunoTertrais) September 3, 2017
"That's very roughly the equivalent 100,000 tons of TNT. Maybe its 20 percent smaller, maybe 30 percent larger," says James Acton, a physicist and co-director of the Nuclear Policy Program at the Carnegie Endowment for International Peace.
Much analysis remains to be done, he notes.
And if it's a hydrogen bomb, as the North claims, that's a big deal
"Normal" nuclear weapons depend on the splitting apart, or fission, of atoms for their explosive power. But for thermonuclear weapons, that's just the start.
A comparatively small fission bomb made of uranium or plutonium is used to trigger a far larger blast through nuclear fusion, the sticking together of light atoms. Those atoms are hydrogen isotopes, which is where the hydrogen bomb derives its name.
Modern nuclear weapons of the sort possessed by the U.S. and Russia are almost all thermonuclear in nature. It allows the weapons to pack a huge punch while fitting in a warhead small enough to be delivered by a missile. These weapons are also tens or hundreds of times more powerful than the ones used at the end of the Second World War.
For his part, Acton says he says no reason to doubt the North Korean claim. "I don't have any serious doubt in my mind that this is what the North Koreans say it is, and that's a thermonuclear weapon."
Kim's nuclear photo op spoke volumes
A day before the test, North Korea released photos of Kim Jong Un posing with a hydrogen bomb, or at least a model of a hydrogen bomb. The photo shows an oblong device that looks a little like a dumbbell. One of the spherical shapes depicted could be the fission "primary" of the weapon; the other the fusion "secondary".
Whether or not the device in the picture is real, the photos are meant to clearly show that North Korea understands the concepts behind modern thermonuclear weapons. A diagram behind Kim also shows how the weapon could fit into a missile warhead.
Earlier this year, North Korea conducted two tests of an Intercontinental Ballistic Missile.
Military options are probably not the greatest idea
In a series of tweets following the test, President Trump opined that the North Koreans "only understand one thing!"
South Korea is finding, as I have told them, that their talk of appeasement with North Korea will not work, they only understand one thing!— Donald J. Trump (@realDonaldTrump) September 3, 2017
However, many analysts believe that even a limited military strike on North Korea could be potentially catastrophic. "No military analyst believes that we would be able to destroy all of North Korea's nuclear weapons or capabilities," says Jon Wolfsthal, a former adviser to Obama's National Security Council who now works with GlobalZero, an arms control nonprofit. "If you're not assured you've got them all, you're triggering a nuclear response."
And the North has thousands of conventional artillery pieces within range of the South Korean capital Seoul. That would mean a devastating nonnuclear response would also be possible.
What happens now?
Nobody knows. Much will depend on how the U.S. and allies in the region respond to the test. Additionally, China may be more willing to apply sanctions and other pressure on the North Korean regime.
Perhaps the greatest unknown is what Kim Jong Un will do with his nuclear arsenal. Traditionally, nations have used these weapons as a way to deter attacks by others, and so far, the young leader's actions seem to suggest he wants to preserve his power, according to Wolfsthal.
But, he adds, "The problem with deterrence is that it works up until the point it doesn't."
More details about this...
Despite bearing the brunt of stiff international sanctions, North Korean leader Kim Jong-un continues to splash cash on personal luxuries and advancing the country’s weapons program.
But if the sanctions are having any effect on Kim’s lifestyle, he’s certainly not showing it. The
Supreme Leader’s recent purchases are thought to include a gleaming white yacht, expensive liquors and even the equipment necessary to kit out a luxury ski resort, according to CNN.
The numbers just don’t add up. In March, North Korea’s state media warned citizens to prepare for economic hardships ahead as the rogue nation channeled funding into its weapons program.
“The path to the revolution is never easy, we might have to go through Arduous March again—in which we only had to eat roots of the grass—and we might have to fight against our enemies all by one’s self,” the editorial said, according to a CNBC translation of the Korean text.
The country has been accused of crimes such as hacking banks, selling weapons, dealing drugs and even trafficking endangered species – operations that could potentially rake in hundreds of millions of dollars.
“That money also helps pay for the country’s nuclear and missile programs, both of which Pyongyang believes it needs in order to deter any US-led attempt at regime change,” experts told CNN.
A 2008 Congressional Research Service report said Pyongyang could generate anywhere from $500 million to $1 billion in profits annually from its ill-gotten gains.
SOUTH KOREA’S BLUNT REPLY TO BOMB
South Korea has launched a ballistic missile exercise in response to North Korea’s provocative detonation of what it claimed was a miniaturised hydrogen bomb.
The drill involved surface-to-surface ballistic missiles and F-15K fighter jets hitting targets off the east coast of South Korea, simulating a strike on a target as far away as North Korea’s nuclear test site, Punggye-ri.
Monday’s drill was carried out by only the Korean military, but more are being prepared with the US forces in South Korea, the statement said.
Photos have emerged of the military exercise, which were distributed by the South Korean Defence Ministry on Monday.
Trump is not ruling out a retaliatory strike against North Korea following its most powerful nuclear test to date, which he called “very hostile and dangerous to the United States.”
It also comes as Prime Minister Malcolm Turnbull called on China to act against the rogue nation.
Defence chiefs and intelligence agency heads have briefed Mr Turnbull and the National Security Committee of Cabinet on the developing situation in North Korea after it claimed to have tested a hydrogen bomb at the weekend.
Mr Turnbull condemned the “shocking” test while updating Parliament on the matter today.
He also confirmed Japan’s prime minister Shinzo Abe and he had agreed to meet with the US government on the matter at the soonest possible opportunity.
Foreign Affairs Minister Julie Bishop said Australia’s response would continue to be “firm, measured and calm”.
Opposition leader Bill Shorten said Australians could be assured there was bipartisan condemnation of North Korea’s “deliberate, dangerous and provocative” testing.
He quoted US Defense Secretary Jim Mattis, saying “if this goes to a military solution, it will be tragic on an unbelievable scale”.
The US leader is set to convene a meeting of his national security team later on Sunday to discuss the American response, with Treasury Secretary Steven Mnuchin drawing up tough new economic sanctions to further isolate North Korea.
President Trump also tweeted that the US “is considering, in addition to other options, stopping all trade with any country doing business with North Korea.”
The tweet suggested he hopes to squeeze China, the North’s patron for many decades and a vital US trading partner, on the economic front, to persuade Beijing to exert leverage on its neighbour.
North Korea’s latest underground blast defied UN resolutions that prohibit Pyongyang from pursuing nuclear and missile programs.
‘NOT TOTAL ANNIHILATION’
After meeting with President Trump and Vice President Mike Pence on Sunday, US Defence Secretary James Mattis read a brief White House statement in response to North Korea’s latest threat.
“We have many military options, and the president wanted to be briefed on each one of them. We made clear that we have the ability to defend ourselves and our allies, South Korea and Japan, from any attack, and our commitments among the allies are ironclad,” he said.
Before walking off, he said: “We are not looking to the total annihilation of a country, namely North Korea, but as I said, we have many options to do so.”
TURNBULL: CHINA MUST ACT
Malcolm Turnbull has redoubled calls on China to rein in North Korea’s “cruel and evil dictatorship” after the hermit kingdom claimed it tested a hydrogen bomb.
Conflict on the Korean Peninsula could now only be avoided by the regime “coming to its senses”, the Prime Minister said this morning.
Mr Turnbull said Kim Jong-un’s nuclear bomb test was a direct affront to China and called for a “strong Chinese response”.