Things really could be worse…

To cheer up all of us cartography/apocalyptic-doom freaks, the South China Morning Post presents a graphic showing the effect on different cities of an atomic bomb identical to Fat Man, dropped on Nagasaki on August 9, 1945. (Specifically: 20 kilotons TNT equivalent, detonated at 1,650 ft.) The concentric circles, dark red to white, represent the radii of: the fireball, air blast at 20 psi, radiation at 500 rem, air blast at 5 psi, and thermal radiation creating 3rd degree burns…


A couple of interesting points…

First, neighbourhoods named Soho seem to escape the worst of it – a case of the devil looking after his own, perhaps, or karmatic compensation for previous tourist invasions. However, as we shall see, Hong Kong’s Soho might be less fortunate.

Second, the area suffering serious damage might look surprisingly small, given that this an atom bomb, after all. If you were in Kennedy Town, Quarry Bay, Sham Shui Po or Kowloon City, you could well survive. If you were in Discovery Bay, you would (as ever) be oblivious to what was happening over there on Planet Hong Kong, give or take the dogs barking at the blinding flash/deafening roar.

Having said all this, the graphic does not take account of topography. With detonation at 1,650 ft above the West Kowloon Cultural Hub-Zone (one benefit), the blast would hit the north-facing hillside of Hong Kong Island at less of an angle, meaning that even the upper reaches of the Mid-Levels would probably be obliterated.

By today’s standards, Fat Man was a small weapon. China’s Dong Feng 5 intercontinental ballistic missile can carry a warhead of 5 megatons, or 5,000 kilotons – 250 times more powerful than the 1945 bomb. The SCMP spares readers the horrors of what this would do. Even the PLA, which likes to hint at wielding its might in our unpatriotic city, has not used this as a clumsy veiled threat, at least not yet. Detonated at around 5,000 metres, it would avoid concentrating the radiation and would spread out the physical blast for optimum effect: the fireball would straddle the harbour; the 5 psi air blast would topple buildings as far away as Tsuen Wan and Shatin; and the 3rd-degree-burn thermal radiation would extend out to Tung Chung, Tuen Mun and Fanling…



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22 Responses to Things really could be worse…

  1. Jason90 says:

    Hemlock, Your graphic seems to have the notional Chinese bomb detonating right above Tamar. Surely some mistake? It would boil the PLA swimming pool and severely blacken the windows at the Liaison Office….

  2. Citizen says:

    Try this Nukemap for more fission fun

  3. editor says:

    What if it *were* your city? Does no one give a fuck about the subjunctive anymore?

  4. gweiloeye says:

    Well that just put a downer on a nice day.

    And just for some more happy thoughts, dont forget the detonation would happen above the ground (100-200 metres) for maximum immediate impact and able to hit the top and both side of the island. Dont want to detonate near the ground, your allies (or yourselves) don’t want radioactive dust covering them for the next millenium …if anyone still alive.

  5. maugrim says:

    The only things that would survive would be cockroaches and Michael Tien.

  6. Tom says:

    @editor: Hong Kong has terminal will/would confusion*, so was/were is a losing battle from the off given that it bedevils many native speakers.

    * By which I mean the “Hong Kong official would”, ubiquitous on public signs and in government writing. “The playground would reopen in early May.” It would but… what? The suspense is unbearable.

    I have a pet theory that this phenomenon is a legacy of decades of prevaricating British civil servants.

  7. @maugrim – is there a difference?

  8. PHT says:

    Maugrim – I think Vagina Yip’s hair would survive too.

  9. Jonathan T Proboscismonkey says:

    400 year old Banyan trees chopped down to save a wall?

  10. Maugrim says:

    Regina displaying her colonoscopy X-rays and weeping at a press conference? If true then my apologies to cockroaches as it’s obvious some creatures will go lower than they.

  11. stinky foot says:

    I think the ‘bomb’ has all ready detonated: CY ‘Fat-boy’ Leung. Let’s look closer to home and not the ‘what ifs’. The fall-out has radiated us all–if the lead doesn’t get us all first. As exhibit one may look at the fact that those, who now know their water is contaminated are forced to eat out rather than cook in their lead contaminated flats. Who can ascertain that the restaurants, food stalls, hospitals, clinics and so on are free from lead? This is a major ‘fat-boy’ event.

    If this government is still on the side of Hong Kong people, this health debacle must be addressed, across the board.

    We may finger-point later, but if this government does not stand up and protect the health of the people, we might as well hide under desks, hold our heads and pray that armageddon is not upon us.

  12. Probably says:

    All a part of the lead up to the glorious public holiday scheduled for 3rd September. To quote the government website “The Government has, by legislation, designated 3 September 2015, the 70th anniversary day of the victory of the Chinese people’s war of resistance against Japanese aggression, on a one-off basis as an additional Statutory Holiday and General Holiday for 2015.”

    This form of English would never have been written by someone educated in god’s own language and so can only be a direct transcript from some sad CCP propaganda exercise.

    Yet another example of Hong Kong so-called government kow-towing.

  13. Knownot says:

    “the PLA, which likes to hint at wielding its might in our unpatriotic city”

    The decision to drop a “Nagasaki bomb” on Hong Kong remains controversial, for both moral and political reasons. On one hand, tens of thousands of people were incinerated (I was one of them). On the other hand, Hong Kong patriots (who were also incinerated) point out that the invasion of China by democracy and the rule of law would have led to even greater loss of life.

    There is, however, no dispute that the immediate aftermath for Hong Kong was disastrous. When the Chief Executive, who was in Iceland when the bomb was dropped, returned, he appointed three committees to oversee reconstruction; their efforts proved ineffective.

    Whether the bombing prolonged the life of the People’s Republic, and if so by how much, time will tell.

  14. Joe Blow says:

    One of them Big Berta’s could easily cream all of Singabore. See, every coin has two sides !

  15. Laguna Lurker says:

    I hardly think a pressure wave of 5 psi would “topple buildings as far away as Tsuen Wan and Shatin”. Ambient atmospheric pressure at sea level is about 14.7 psi, or 1 atmosphere.

    Even a pressure washer can exert up to 1,450 psi, but it is unlikely to be capable of bringing down a building—unless, of course, it was built by a mainland contractor.

    Don’t believe what you read in the SCMP.

  16. Nimby says:

    Laguna Lurker.

    You got to be a banker, right?

    Think compound interest. It’s not just the interest rate, but also the amount of capital that counts. That’s <5 pounds per square inch. You have to multiply that pressure difference over the surface area affected. ATM pressure is applied 360*. Something like HSBC’s steel shell building (like the steel dome frame in Hiroshima) might remain standing after a blast, because every window, stick of furniture and person inside it presenting any surface area to the blast will be blown out the back of the building and into the hillside behind it, where as a typical el-cheapo, hell with the environment ferro concrete wall of Superman Li housing/HKPH** even way up in Tunmun will keel right over ( ***lets block the airflow for every building and street behind us so our 14″ windows can view at some angle of the harbour if we stand on a step ladder).

    A pressure washer only maintains it’s force over about 0.1 to 0.2 square inches, and it very rapidly dissipates after leaving the nozzle thanks to internal vortex and air-friction. Most importantly, the mass leaving it at any one moment is very small, so the energy it contains is small (remember small motor = small amount of energy). It might cut your skin if close enough but it won’t knock you over. Try standing up to a fire hose at 1/8 the pressure, which usually won’t cut your skin, but will pulverize every bone in your body if close enough.

    Last bit of unsolicited advise, the SCMP reporters are hardly going to go through the effort to do the calculations, much less be capable of doing so, so they just copied/pirated information off of some websites, like the Union of Concerned Scientist.

  17. LRE says:

    Also the 5psi of overpressure (so 20psi in total) arrives rather quickly — about Mach 1. That’s quite some windspeed – about a T30 on the typhoon scale. But detonation heights are generally calculated to give the maximum range for 10 psi (using Mach stems to increase the pressure), so 5psi is very much outside the full damage blast radius.

    On the plus side, if they survive the blast, at least the lead levels in public housing estates water pipes should make the water safer to drink than everyone else’s.

  18. Big Al says:

    @Jonathan T Proboscismonkey – PCMP’s inelegantly written “4 century old trees” means 4 x 100 year old trees, not 400 year old trees. I don’t believe there were many walls in Sai Ying Pun in the 1600s!

    @stinky foot – don’t you see the glorious of the CY Leung administration? Providing free lead in water to protect people from bomb-induced radiation!

  19. Nimby says:

    forgot to add to
    “Try standing up to a fire hose at 1/8 the pressure, which usually won’t cut your skin, but will pulverize every bone in your body if close enough.”
    the following:
    This proven ability to pulverize bones is exactly what the Hong Kong Police want to order Turkish water cannons, none of that wimpy Chinese made stuff.

  20. Laguna Lurker says:

    @Nimby / LRE: Not a w̶a̶n̶k̶e̶r̶ banker but a retired ignoramus. Thanks for enlightening me. I stand corrected.

  21. Big Al says:

    @nimby – lead-containing water sourced from public housing estates, one hopes!

  22. stinky foot says:

    @Big Al, ‘To get sick is glorious’ may be Fatboy Leung’s contribution to the Marxist lexicon of approved patriotic texts. Meter-high portraits of the ‘glorious one’ coming soon to the housing estates in your neighborhood.

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