North Korea’s nuclear capability is growing, apparently very quickly. Evidence indicated that the device detonated underground on Sept. 3 may have been up to 12 times more powerful than anything the country had previously tested. Original intelligence estimated the device’s yield at 100 kilotons, but later satellite image analysis suggested a much larger explosion. The regime claimed it was a hydrogen bomb that would fit in a missile capable of reaching the mainland United States.
It was North Korea’s sixth nuclear test, the third in two years, and the first since President Trump took office. North Korea in July tested an intercontinental ballistic missile believed to be capable of traveling thousands of miles. The nation has conducted 18 missile tests this year.
North Korea missile
launches and nuclear tests
Note: Launch days are North Korean local time. Does not include cruise missiles.
Nuclear tests by yield
Estimates in kilotons
< 1kt
4 kt
10 kt
6 kt
10-20 kt
250 kt
Source: CSIS Missile Defense Project, Nuclear Threat Initiative, University of Hamburg,
Washington Post reports
THE WASHINGTON POST
North Korea missile launches
and nuclear tests
Note: Launch days are North Korean local time. Does not include cruise missiles.
Nuclear tests by yield
Estimates in kilotons
10 kt
10-20 kt
6 kt
4 kt
< 1kt
250 kt
Source: CSIS Missile Defense Project, Nuclear Threat Initiative, University of Hamburg, Washington Post reports
THE WASHINGTON POST
How strong would the blast be?
Blast radius depends on some variables, particularly the altitude at which a bomb is detonated. Energy from a bomb that goes off in the air travels differently than a bomb that doesn’t detonate until it hits the ground.
Here is how explosions would compare if each of these five bombs were to be detonated one kilometer above the ground, according to the fairly terrifying NukeMap calculator at NuclearSecrecy.com.
DAMAGE SCALE
Fireball
Most living things would
be incinerated.
Radiation
Radiation would kill 50-90 percent of people within
hours to weeks.
High-pressure blast radius
The air blast would destroy most heavily-built concrete structures.
Low-pressure blast radius
Most residential buildings
would collapse.
Thermal radius
Thermal radiation would cause third- degree burns on most people.
NUCLEAR BLASTS COMPARED
250kt
Size tested on Sept. 3 by North Korea
Detonation
one kilometer
(0.6 miles)
above ground
Radius of
damage
0
4.2 miles
Little Boy
Bomb dropped in 1945 over Hiroshima
0
1.1 miles
B83
Largest nuclear bomb in current U.S. arsenal
0
8.5 miles
Dong Feng-5
The largest in China’s current arsenal
0
15.5 miles
Tsar Bomba
Largest ever tested
(Soviet Union, 1961)
0
5 miles
37.3
miles
DAMAGE SCALE
High-pressure
blast radius
Low-pressure
blast radius
Thermal
radius
Fireball
Radiation
Most living things
would be incinerated.
Radiation
would kill
50-90 percent
of people within hours to weeks.
The air blast would destroy most heavily-
built concrete structures.
Most residential buildings would collapse.
Thermal radiation would cause third-
degree burns on most people.
NUCLEAR BLASTS COMPARED
250kt
Size tested on Sept. 3 by North Korea
Little Boy
Bomb dropped in 1945 over Hiroshima
B83
Largest nuclear bomb in current U.S. arsenal
Detonation
one kilometer
(0.6 miles)
above ground
Radius of
damage
0
0
1.1 miles
0
8.5 miles
4.2 miles
Dong Feng-5
The largest in China’s current arsenal
Tsar Bomba
Largest ever tested
(Soviet Union, 1961)
0
15.5 miles
0
5 miles
37.3 miles
We chose that detonation altitude because the intelligence community estimates that North Korea’s most recent intercontinental ballistic missile test broke apart at about that height.
About this story
Sources: Catherine Dill, senior research associate at the Middlebury Institute of International Studies at Monterey in California; CSIS Missile Defense Project; Nuclear Threat Initiative; University of Hamburg; blast radius data from Alex Wellerstein’s NukeMap at The Nuclear Secrecy Blog; Washington Post staff reports.
Originally published Sept. 3, 2017.
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