First of all thanks in advance. I need suggestions on how a five man special ops team can sink an island entirely.


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    $\begingroup$ We need to know a little more about your setting. Since you've said science fiction, what technological level are you giving them for example. $\endgroup$ – Separatrix Sep 4 '17 at 11:43
  • $\begingroup$ How big is the island? What kind of location is it in? Covered in ice, volcanic, coral? $\endgroup$ – nzaman Sep 4 '17 at 11:47
  • $\begingroup$ The easiest thing I can think of is an island in a lake/river and they blow up a dam upstream. $\endgroup$ – Raditz_35 Sep 4 '17 at 11:57
  • $\begingroup$ You cant sink most islands as they are mountains attached to the sea bed. You can flood them. The only islands you can sink are ones made of ice or other floating material. $\endgroup$ – Bellerophon Sep 4 '17 at 12:09
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    $\begingroup$ Is this about humans on Earth? $\endgroup$ – a CVn Sep 4 '17 at 12:24

If the island is small enough and the SoF team has access to modern mechanized transport, they can always transport themselves and a thermonuclear device on location and find a way to place the device below ground (either a natural cave or cavern, or an underground bunker, service shaft or similar construction).

Of course these guys need to have been working out for a while, since to entirely remove an island from the face of the Earth needs something like "Castle Bravo"

enter image description here

Castle Bravo detonation

OK, so maybe it isn't technically "sinking", but the crater will be well below sea level when finished.

  • $\begingroup$ You don't need modern mechanized transport. Remember, this is an island--accessible to the sea. Attach lighter-than-water (but not inflated!) floats to the bomb to give it a small positive buoyancy. Attach an anchor to it to give a slight negative buoyancy. Now you can swim the bomb to it's target. (The slight negative buoyancy is within the range of what the divers can compensate for with their personal compensators.) $\endgroup$ – Loren Pechtel Sep 4 '17 at 21:51
  • $\begingroup$ The Castle Bravo device was housed in a cylinder that weighed 23,500 pounds (10.5 long tons; 11.8 short tons) and measured 179.5 inches (4.56 m) in length and 53.9 inches (1.37 m) in diameter. So yes, they will be needing a bit more than their bare hands...... $\endgroup$ – Thucydides Sep 5 '17 at 3:29
  • $\begingroup$ We can do a lot better than that--with modern design 15mt should weigh no more than 3,000kg. At neutral buoyancy they could move it--ever push a car? Since it's 5-man team that's only 600kg/person. $\endgroup$ – Loren Pechtel Sep 5 '17 at 4:06

Either the island moves down or the sea level rises, both have their difficulties (understatement) and side effects.

Islands are attached to the Earth

So first off we need to consider that to move an island down you need some way to move enough of the material that lies between it and the sea bed, they don't float so can't be 'sunk' as such. This all changes if you've designed a floating island but I expect you would have mentioned that.

The easiest way would be for the (small) island to be sitting on top of a cave system full of air or underground lakes - possible if your island is sitting on a layer of softer rock. If your island is on a fault line and your five man team is willing to put in a lot of time then you could cause an earthquake to bring the island down to fill the gaps the air/water once occupied and leaving the space above to be filled in by water.

Aside from that you're looking at digging tunnels beneath to create this effect, not a quick job and a high chance of being discovered - the collapse may not be total, it could sink in parts.

Water rising

This is perhaps more likely...but again still difficult, its all a matter of volume and position. If your island is in the middle of a lake with a dam then you're in luck, the lake is a small area so a rise of a few meters is much less water than if your island is in the middle of the ocean. Blowing a dam or diverting a river are possible solutions for flooding a lake. Otherwise you're looking at melting ice caps and flooding everything that lies as low as your island.

The consequences are important. You can't raise the level of the ocean to flood an island and expect the rest of the world to be fine. Equally if an island sinks the volume of water that is going to start rushing about has to go somewhere. Earthquakes at sea have been known to cause tsunamis.

All in all, if you're looking for a quick in and out job rather than a prolonged engineering project then you need explosives, a dam and your island to sit in the middle of a lake.


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