North Korea’s Other Threat
The world is often alarmed at North Korea’s missile and nuclear programs, but thousands of Cold War-era artillery are also massed on the border with South Korea, capable of firing a massive barrage on the capital Seoul with little warning.
The two Koreas remain in a technical state of war since the 1950-53 Korean War ended in a truce, not a peace treaty. When tensions are high, Pyongyang often threatens to rain a “sea of fire” on Seoul and its 10.2 million people living 40 km from the border.
Threats from the North
Mentions of a “sea of fire” in North Korean media since 2000
The border dividing the two Koreas is one of the most heavily guarded in the world. The Demilitarised Zone (DMZ) is a 4-km wide buffer of landmines and razor wire stretching 245 km across the middle of the Korean peninsula. Heavy weapons and hundreds of thousands of North and South Korean soldiers are forward deployed on either side of the border. Some 28,500 American troops are also stationed in South Korea.
Pyongyang does not comment on its military deployment, but experts believe most of North Korea’s 13,600 guns and multiple rocket launchers are positioned near the DMZ. Its conventional arsenal includes large caliber guns and multiple rocket launchers that experts consider effective despite their mostly outdated design.
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Heavy guns, either towed or self-propelled, comprise the bulk of North Korea’s artillery. Many are variants of older Soviet and Chinese guns. The 170mm “Koksan” gun is a domestic design first seen by Western experts in 1979. It’s 60 km (37 miles) range is the longest of North Korea’s field guns.
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North Korea is working to extend the reach of its mobile rocket artillery. The 240mm Multiple Rocket Launcher System (MRLS) can fire a volley of 12 or 22 long-range rockets from tubes mounted on a heavy truck. The 240mm launchers deployed near the DMZ have a range of 60 km. State media showed images of a new longer range 300mm launcher in 2016 but its deployment is not known.
Northern artillery is potentially vulnerable to air strikes and counter-battery fire from South Korean and U.S. forces. To reduce that risk, the weapons are housed in Hardened Artillery Sites (HARTS) are built into caves or man-made bunkers. While some guns can fire from protected sites, heavier weapons risk detection because they must fire from outside a bunker or shelter.
For example, a 240mm MRLS can fire a 22-rocket salvo in 44 seconds but it can take a crew up to four minutes to lower the truck-mounted launcher, raise the ground stabilizing pads and return to hardened shelter. Experts suggest the North would not fire its weapons in an all-out barrage but stagger an attack to reduce the risk of counter measures.
Hardened artillery sites (HARTS)
Many HARTS entrances face away
from the South, making them
harder to hit.
Map data: CNES / Airbus
Constructing a hardened site
Satellite images show the process of the hardened artillery sites being built.
Hardened artillery sites did not exist.
Land is excavated at chosen sites.
CNES / Airbus
Hardened structures placed, likely made of concrete.
CNES / Airbus
Bunkers covered with earth. Firing points and rest of site completed.
What’s in range
If the North launched an artillery barrage on the South, military experts say long range weapons such as the “Koksan” 170mm guns and 240mm rocket launchers could reach Seoul. The map below shows the maximum range of these weapons plotted from hardened artillery installations and their theoretical reach into the Seoul metropolitan area.
Hardened artillery sites
60km artillery range
If there is an artillery attack, South Korea’s government says people should stay “calm and quickly evacuate to shelters”. A smartphone app from the Ministry of Public Safety and Security offers guidance to the nearest shelter, such as an underground subway station or shows safe areas below office and government buildings.
Circles show underground shelters. The scale of the circle represents the size of the shelter.
The largest shelter in the
239,096 square metres,
is located underneath
an apartment complex.
There are 17,501 shelters across South Korea, with 3,321 civil defense evacuation facilities in the city of Seoul, according to the ministry.
23.69 sq km
Based on this combined area, the shelters would provide each of the city’s 10.2 million inhabitants an average of 2.31 square meters of space.
2.31 sq meters
* Popluation density is based on the number of people per grid cell. The size of a grid cell is 100m x 100m at the Equator.
Sources: Curtis Melvin, U.S.-Korea Institute at SAIS, Johns Hopkins University; Nautilus Institute for Security and Sustainability; International Institute for Strategic Studies; Global Security; Federation of American Scientists; RAND Corporation; KCNA Watch; LandScan, Oak Ridge National Laboratory; WorldPop Project, University of Southampton Global Health Research Institute; Ministry of Public Safety and Security, South Korea; OpenStreetMap; Reuters
By Simon Scarr, Weiyi Cai, Wen Foo and Jin Wu | REUTERS GRAPHICS
Additional reporting by James Pearson. Additional editing by Darren Schuettler.