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Marian Perera
10-31-2013, 01:16 AM
Hi guys,

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.

He has two ships, way out at sea, both loaded with tons of explosive. His plan is to send the explosive to the sea bed and then detonate it. Somehow. This being a fantasy with a world in the middle of the Industrial Revolution, I'm still trying to figure that part out, so any help along those lines would be appreciated.

My other problem is, I read that the US tried tsunami bombs in 1945, and discovered that it took two million kg of explosive to cause one. Obviously my poor antagonist's two ships are not going to be carrying a million kg each. This is a fantasy so I'm not hewing rigidly to the requirements of reality, but I'd still like things to be as plausible as I can make them. Are there any conditions you can think of which would make the tsunami bomb more likely to be effective?

Thanks in advance. :)

Russell Secord
10-31-2013, 01:24 AM
Well, a natural tsunami comes from an earthquake. Find an undersea fault line, drop the explosives into that, and cross your fingers.

Torgo
10-31-2013, 01:28 AM
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'.)

TheNighSwan
10-31-2013, 01:50 AM
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.

thothguard51
10-31-2013, 01:59 AM
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...

PorterStarrByrd
10-31-2013, 01:59 AM
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.

Helix
10-31-2013, 02:07 AM
This book extract that covers the tsunami bomb (Project Seal) might give some ideas: The best kept secret of WWII (http://www.nbr.co.nz/article/best-kept-secret-world-war-two-%E2%80%94-project-seal-tsunami-bomb-ck-134614).


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.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.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!

Wilde_at_heart
10-31-2013, 02:17 AM
Are you familiar with Tesla's Earthquake machine?

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

King Neptune
10-31-2013, 04:04 AM
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

ULTRAGOTHA
10-31-2013, 04:10 AM
http://en.wikipedia.org/wiki/La_Palma

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 (http://geology.com/records/biggest-tsunami.shtml)

Marian Perera
10-31-2013, 05:18 AM
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.

You know, that's an amazing idea.

Get people thinking that the wave will originate from the sea bed, and in actuality, have the explosives on a cliff somewhere. At least now I don't have to figure out how he detonates explosives on the sea bed.

And thanks so much for the link with the video. I loved watching that - the water crashing down, the birds taking off in a shrieking mass, the anchor chain snapping. Great stuff for the book.

Marian Perera
10-31-2013, 05:19 AM
Are you familiar with Tesla's Earthquake machine?

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

No, I'm afraid I have no idea what either of those are. But I will do the research. :)

Marian Perera
10-31-2013, 05:22 AM
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.

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.

Marian Perera
10-31-2013, 05:27 AM
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?

I picked up an Alex Rider novel once, and, for some reason, read the ending first. In it, the main character got shot in the chest and was presumably dead. I was so bummed by that I didn't read anything else, even though I later found out that he survived (of course). Somehow a teenager getting almost fatally shot really bothered me.

But if there's a novel where someone creates a tidal wave, I'll read it.

Marian Perera
10-31-2013, 05:28 AM
If this is fantasy, and magic is available in your world, use magic to cause a fault line to rise/drop.

Unfortunately no magic is available to the main characters. It's just them, their wits and what technology is available at that point in time (they're on a steamship powered by propellers, and for weaponry I'm thinking cannons and Greek fire).

Marian Perera
10-31-2013, 05:30 AM
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.

I was thinking of that too. It can be one of the ideas on the table when the hero and heroine are discussing how the antagonist could pull this off.


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.

Even a cargo ship of that age and time? Maybe I need to research this some more.

cbenoi1
10-31-2013, 05:49 AM
> 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/State-Fear-Michael-Crichton/dp/0061782661


-cb

blacbird
10-31-2013, 06:14 AM
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

cornflake
10-31-2013, 08:01 AM
So beaten to the Canary Island punch. :gaah

IClaytonR
10-31-2013, 08:47 AM
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.

blacbird
10-31-2013, 10:11 AM
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.

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

IClaytonR
10-31-2013, 03:12 PM
By no means is the Cascadia subduction zone a matter of "lesser extent".

Agreed. My apologies. I stand corrected. :)

King Neptune
10-31-2013, 04:36 PM
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.

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.

Marian Perera
10-31-2013, 08:43 PM
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.

Well, what I now have in mind, with input from this thread, is this:

The terrorist has two ships anchored at an island, one before the explosive-laden cliff and the second on the island's other side. He's in ship #2, hoping the island will shield him from the worst of the blast. Ship #1 is what the protagonists see first, and they don't know he has two ships, so they're not likely to go around the island searching for more, especially since they believe the explosives are all on the sea bed directly below ship #1. So that's the one they'll concentrate on.

The cliff is going to fall, one way or another. I just have to decide on what level of destruction it produces, because while I don't want to kill off thousands of people, which would be a pretty sad ending for a romance, I do love the image of this great wall of water rushing down on a ship. Maybe the protagonists manage to neutralize some of the explosives, but not all of them.


Someplace near the Azores probably could work well.It's a romantic fantasy. I can manipulate the geography as needed. :)

mirandashell
10-31-2013, 08:53 PM
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.

Marian Perera
10-31-2013, 09:12 PM
I figured a tsunami originating from the ocean bed wouldn't produce a ginormous wave until it was closer to the coast, but what about a wave caused by a massive slab of island breaking off and striking the water?

IClaytonR
10-31-2013, 09:30 PM
I figured a tsunami originating from the ocean bed wouldn't produce a ginormous wave until it was closer to the coast, but what about a wave caused by a massive slab of island breaking off and striking the water?
I honestly think this is your best bet. Exploit a fracture in a slab of a volcanic island and drop a giant chunk into the water, causing an enormous wave. The Canary Island case gives you all the info you need on how it would work, and you could use that island or just invent one. The good thing about that scenario is that it does not have to be at an active volcano or fault line. It only needs be where there was once volcanic activity, which leaves many possibilities.

http://news.bbc.co.uk/2/hi/science/nature/1513342.stm

IClaytonR
10-31-2013, 09:34 PM
Whether the ship would succumb to a wall of water if it was in splash zone of the rockfall, would depend very much on how the rock fell. That's beyond my expertise.

Marian Perera
10-31-2013, 09:34 PM
I honestly think this is your best bet. Exploit a fracture in a slab of a volcanic island and drop a giant chunk into the water, causing an enormous wave.

Plus, then we don't get into the whole "light a fuse to something that's on the sea bed" problem.

But the protagonists believe that that's how the antagonist is going to set off the wave, so they send someone searching underwater and that person gets caught and yeah, things get rough from there.

It's going to be an invented island, since this is a fantasy set on an alternate world, but I'll be drawing heavily on the Canary Island scenario for inspiration.

IClaytonR
10-31-2013, 09:46 PM
1958 Lituya Bay megatsunami


http://en.wikipedia.org/wiki/1958_Lituya_Bay_megatsunami

ULTRAGOTHA
10-31-2013, 10:18 PM
Well, what I now have in mind, with input from this thread, is this:

The cliff is going to fall, one way or another. I just have to decide on what level of destruction it produces, because while I don't want to kill off thousands of people, which would be a pretty sad ending for a romance, I do love the image of this great wall of water rushing down on a ship. Maybe the protagonists manage to neutralize some of the explosives, but not all of them.

Then I think Lituya Bay is a good idea. You've seen the video on that link I posted. You can have your protagonist's ship a mile or so from the cliff and they get hit by the huge wave, which then goes on past them. Set up your body of water to be not so narrow as Lituya bay and your city on higher ground and you could have a far smaller event.

But people are going to die if you have a big enough wave close enough to the city. Or your Antagonist could totally underestimate the damage his set-up will cause and all it does is send a big splash of water over your Protagonists' ship.

Remember at Lituya bay the spar of land the second set of witnesses were swept over was seven miles from the site of the landslide and their boat went over it at at least twice tree height. The narrow confines of the bay gave the water nowhere else to go. If your body of water is wider, the wave won't be so intense.


ETA: I'm not an expert in explosive physics, but I would think that explosives in a ship at the base of a cliff won't give you a Canary Island scenario, you'd just get a bunch of debris in the water. For an event close to the Canary Island theory, you'd need to put your explosives on the other side of the cliff so a huge solid chunk breaks off.

King Neptune
10-31-2013, 10:27 PM
Well, what I now have in mind, with input from this thread, is this:

The terrorist has two ships anchored at an island, one before the explosive-laden cliff and the second on the island's other side. He's in ship #2, hoping the island will shield him from the worst of the blast. Ship #1 is what the protagonists see first, and they don't know he has two ships, so they're not likely to go around the island searching for more, especially since they believe the explosives are all on the sea bed directly below ship #1. So that's the one they'll concentrate on.

The cliff is going to fall, one way or another. I just have to decide on what level of destruction it produces, because while I don't want to kill off thousands of people, which would be a pretty sad ending for a romance, I do love the image of this great wall of water rushing down on a ship. Maybe the protagonists manage to neutralize some of the explosives, but not all of them.

It's a romantic fantasy. I can manipulate the geography as needed. :)

The actual fault probably has the features that you want. It is partly visible on the surface, and I believe that there are caves in the volcanic cone. There are detailed maprs of the volcano online. This one tries to debunk
http://www.lapalma-tsunami.com/tsunami.html
the fault line
http://www.google.com/imgres?imgurl=http://www.geo.arizona.edu/~andyf/LaPalma/LAPALMA2.jpg&imgrefurl=http://www.summitpost.org/la-palma/390279&h=799&w=606&sz=222&tbnid=Vn4EQXgKUsh5_M:&tbnh=90&tbnw=68&zoom=1&usg=__d0GjuFgbIIMPplqFrW2w4AENHw4=&docid=cGAMcq2DvextfM&sa=X&ei=751yUtq0FszC4APol4BA&ved=0CEMQ9QEwAg
Article about island with excellent photo and details of collapse and a link to the paper that started the story
http://www.summitpost.org/la-palma/390279

If you search, you wll find even more. This is a neat issue, and theere are ways to stretch it into other maters also. Such as knocking loose the West Ice Shield of Antarctica when the tsunami.

On the other hand, it is not unlikely that the chunk that's supposed to fall will hang up and take days to slide into the ocean. You could put ship 1 near it and describe the ship being dragged in with the rocks.

Marian Perera
10-31-2013, 10:34 PM
ETA: I'm not an expert in explosive physics, but I would think that explosives in a ship at the base of a cliff won't give you a Canary Island scenario, you'd just get a bunch of debris in the water. For an event close to the Canary Island theory, you'd need to put your explosives on the other side of the cliff so a huge solid chunk breaks off.

No, the explosives are on the island. The antagonist and his crew can take some time to bury them securely before the protagonists show up. That's exactly what they're hoping will happen, that a huge solid chunk of the cliff breaks off and smashes down.

I almost wish this was all happening in a bay, so I'd be sure to get that roaring rush of water, but the only reason the antagonist feels safe at all is because it's all happening out to sea, and at least some distance out that he's not afraid of multiple warships coming to surround him - though now that I come to think about it, he'd probably set the explosives off if he saw anything of the sort. Still, I wanted the protagonists' ship to get temporarily stuck in a crazy version of the Sargasso Sea before they reached this island, so they have to be out at sea.

mirandashell
10-31-2013, 10:42 PM
Ah I see!

I reckon you could make that plausible enough that the vast majority of readers (who aren't experts on this stuff) will accept it.

Plus it will resonate with many cos they live in the areas the wave will hit when this happens IRL.

King Neptune
10-31-2013, 10:47 PM
I almost wish this was all happening in a bay, so I'd be sure to get that roaring rush of water, but the only reason the antagonist feels safe at all is because it's all happening out to sea, and at least some distance out that he's not afraid of multiple warships coming to surround him - though now that I come to think about it, he'd probably set the explosives off if he saw anything of the sort. Still, I wanted the protagonists' ship to get temporarily stuck in a crazy version of the Sargasso Sea before they reached this island, so they have to be out at sea.

The Canaries are fairly close together, so there would be rushing water, and debris from one island would get washed to another, etc. Look carefully at the last of those link I included. Having the islands all around would also damp down the waves.

Move it to the Azores and have them go through the Sargasso Sea.

Marian Perera
11-02-2013, 10:53 PM
The Canaries are fairly close together, so there would be rushing water, and debris from one island would get washed to another, etc. Look carefully at the last of those link I included. Having the islands all around would also damp down the waves.

That's a great idea. I wanted the heroes to pretend to have sailed away, while leaving a Trojan horse behind for the antagonist, and some small islands nearby would do very well for that.

Plus, if there's just one island out in the middle of the ocean, the heroes might get the idea to see if there's anything anchored behind it, but if there are multiple islands...

I checked the link and will be reading through all the info again, because when I did the outline last night, the protagonists ended up on the island itself. I'll have to see what happens after that.

King Neptune
11-02-2013, 11:40 PM
That's a great idea. I wanted the heroes to pretend to have sailed away, while leaving a Trojan horse behind for the antagonist, and some small islands nearby would do very well for that.

Plus, if there's just one island out in the middle of the ocean, the heroes might get the idea to see if there's anything anchored behind it, but if there are multiple islands...

I checked the link and will be reading through all the info again, because when I did the outline last night, the protagonists ended up on the island itself. I'll have to see what happens after that.

Have a good time with it. There's a lot that one can do with earthquakes. L. Sprague de Camp wrote a long short story about people who hijacked a new continent that was created when earthquakes were induced in the South Atlantic. I'm surprised it hasn't been made into a movie.

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