Tsunami bomb

Well, a natural tsunami comes from an earthquake. Find an undersea fault line, drop the explosives into that, and cross your fingers.

Anthony Horowitz did this in one of his Alex Rider books, I'm fairly sure; and isn't it in a couple of Bond movies? (A View To a Kill and that Connery one that ends up on the oil rig?) Whether or not it's scientifically cogent, it's plausible enough that it works as a plot point.

(The response to the objection that there's not enough bang can be 'but it's super carefully targeted'.)

I remember an episode of Myth Busters were they tried to create surfable waves in a lake with explosives; even with high quantities of explosive, it turned out to be extremely difficult, because bombs create *circular* waves that are quickly absorbed and dissipated by the surrounding water, whereas a tsunami is generally closer to longitudinal wave, at least on a local scale.

So either you need a very powerful explosive —2 million kg of explosive happens to be the equivalent of a 2 kilotons atomic bomb. This is 10 times less powerful that the first nuclear bomb that was actually tested, so it would be a very small bomb that would probably be not that hard to create with industrial technology.

Or they could release the explosive around a known seismic fault in order to trigger a submarine earthquake that would result in a tsunami, though I have no idea about the effective feasability of this.


On the other hand, from a pure cargo size consideration, 2 million kg of explosive is not that much, as cargo ships can carry dozen of thousand of tons of material. It would just be difficult to get that much explosive together without attracting attention, and ridiculously dangerous to carry around.

If this is fantasy, and magic is available in your world, use magic to cause a fault line to rise/drop.

As others have said, this is an extremely difficult thing to produce with results that are far from certain...

Possible alternative .. threaten a tsumani while placing an equivalent amount of explosive in an important port. Blow that up while they are trying to figure out where and how to counter the threat.

This book extract that covers the tsunami bomb (Project Seal) might give some ideas: The best kept secret of WWII.

The boffins in the Hauraki Gulf determined that a line or array of massive charges totalling as much as two million kilograms, split up into 10 or so equal parts, detonated around 8km from shore, would produce a wave of 10-12m in height.

One problem that the programme discovered was that the depth at which the explosive was placed was critical: even a small deviation from optimum would rob the wave of energy and the tsunami would be a ripple rather than a roar.

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From that came this:

When it was completed, the report called The Generation of Wave Systems tabulated and analysed the statistical and scientific data from Project Seal and it remains today an interesting handbook of how to make waves.

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I don't know if that report is readily available, but it might be a handy text to consult. It'd be a nice thing to stick in a bibliography!

Are you familiar with Tesla's Earthquake machine?

Some tinfoil hatters claim HAARP can cause earthquakes as well. Maybe something along those lines?

Then there's that chunk of island in the Canaries (La Palma) that some people think will split off and cause a tsunami. It is one side of a volcano that has a fault running diagonally through it. You could have your characters plant large, and I mean shiploads, of xplosives in drill holes along the fault. Who knows? It might even work.

http://en.wikipedia.org/wiki/La_Palma

King Neptune said:

http://en.wikipedia.org/wiki/La_Palma

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Darn you, King Neptune, you beat me to it! <shakes fist>

That's more of a probability (large chunk being blasted off a cliff into the ocean) than a ship load of explosives causing a tsunami.

Here's another link to an actual wave in Alaska:

The largest recorded tsunami was a wave 1720 feet tall in Lituya Bay, Alaska

> I have a scenario where a terrorist sends a message to his country's
> government, saying he will cause a tidal wave if they don't meet his demands.

Same basic plot as Michael Crichton's State of Fear. They used some sort of mining gear to drill holes deep into an unstable crevasse in the ocean, IIRC.

http://www.amazon.com/dp/0061782661/?tag=absowrit-20


-cb

Big tsunamis, like the 2004 Indian Ocean and 2011 Japan events, involving the upward heaving of a vast quantity of water over a wide area, resulting in huge waves having very long wavelengths and traveling very rapidly. Not even the largest nuclear weapons ever devised by humans come anywhere close to the energy release of one of these events.

Nova has produced two magnificent documentaries on these events:

The Wave that Shook the World
Japan's Killer Quake

If you really want to know how a real live tsunami works, find these and watch.

caw

So beaten to the Canary Island punch.

If this takes place in our world, I would explain it in different ways depending on where the tsunami is targeted. For example, if you're targeting the east coast of the United states, the Canary Island example is about your only plausible scenario because the Atlantic ocean is expanding, there are no subduction zones or volcanic arcs. Now, the mediterranean is a subduction zone where the African continent is pushing under Europe, and the Pacific ocean is expanding both ways creating subduction zones at Japan, the Aleutians, and to a lesser extent, the Cascades. Essentially everywhere in the ring of fire has a potential for Tsunamis.

How it generally happens is that as one plate pushes under another, it bends the edge of the upper plate down, and at some point, it releases and springs back up. The stress bows the land upward as it pushes down the edge as well, so there's the double action of the edge springing up, and the bow behind it dropping down. This is what happened in Japan a few years ago and is poised to happen again near Tokyo any time. Japan built sea walls to slow a tsunami if it was to happen, but they were built on that raised bow, so that the sea walls dropped down below the surface of the water when the tsunami was created. Therefore it did not stop it at all.

Another huge volcanic arc is Indonesia. Large volcanoes have caused large tsunamis there as well as the springing of subduction zones.

So, if you are dealing with subduction zones, a mastermind that had a very intimate knowledge of geology, might target a very stressed zone with a major explosion along a subductive fault line.

If it is not along a volcanic arc or subductive fault line, the best bet would to be to collapse a huge chunk of earth into the water, such as a weak volcano, like the example in the Canary islands.

IClaytonR said:

Now, the mediterranean is a subduction zone where the African continent is pushing under Europe, and the Pacific ocean is expanding both ways creating subduction zones at Japan, the Aleutians, and to a lesser extent, the Cascades.

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By no means is the Cascadia subduction zone a matter of "lesser extent". this 1000-mile subduction rupture in the Earth's crust is as dangerous as the rupture of the north Japan subduction zone was. We know it broke in the year 1700, and produced a Pacific-wide tsunami that killed thousands in villages along the coast of Japan. It is formed by the Juan de Fuca Plate, a geographically small plate, being jammed under the North American Plate. But it is capable of producing 9-point Richter scale quakes, and tsunami very similar to that of Japan or Sumatra. It lies along the coast from northern California to the northern tip of Vancouver Island, and along that coastline are Portland, Seattle and Vancouver, among many smaller communities. It is estimated by seismologists to break every several hundred years or so. We're now 313 years along since the last one.

There were, by the way, no really large cities along the coast of northern Japan when the 2011 event occurred. 25,000 people were killed by that tsunami.

caw

blacbird said:

By no means is the Cascadia subduction zone a matter of "lesser extent".

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Agreed. My apologies. I stand corrected.

Queen of Swords said:

I'm afraid that wouldn't work, because for story purposes (it's a romantic fantasy), I need my hero and heroine out on a ship, racing to counter the tidal wave threat. If there's no actual tidal wave threat, their part of the story kind of falls flat, and if I keep them in port, there's no way they could spend enough time with each other.

Also, I want the sheer epic-ness of a tidal wave, the fact that it can and will wipe several coastal towns off the map in a single impersonal blow. Destroying a port with explosives is powerful, but not as much as a tidal wave, IMO.

Plus, the title of the manuscript is The Highest Tide, so there's got to be an actual wave.

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The La Palma idea might work well for you. Some people predict that it will devastate the coasts of the North Atlantic. If you want it to fizzle, then that's fine also, because there are other people who think that the chunk of rock would fall too slowly to cause a tsunami.

If you want something new and different, then you could dream up a huge undersea volcano somewhere of the mid-Atlantic ridge. It could be at Iceland or somewhere more central. There is a finite chance that the spreading center could open substantially at any time.
Someplace near the Azores probably could work well.

Hmmm.... I'm not definite about this but I don't think a tsunami becomes a tsunami until it approaches the coast and gets lifted by the curve of the land. Out in the middle of the ocean, it will go right under a ship without being noticed.