Wiping out Manhattan and California

I keep reading that global warming will melt the polar ice caps, in turn raising the ocean levels by several feet, wiping out the usability of most islands and the coasts. Can i artificially create this by exploding a multi-megaton nuclear device under a polar ice cap, causing all the surrounding ice to melt, or would the resulting melt just be a drop in the bucket? You’d get a higher kill ratio by exploding it in the heart of NY or LA, but there are no policemen or theatre defense weapons by the Poles to stop you. Also, would exploding the same multi-megaton nuclear device over the San Adreas fault create a large-scale disaster, bringing on the BIG ONE and sending California off into the oceans? They did this in Superman, glossing over the millions of deaths caused by the actual explosion itself, but hey, it was a PG movie and not that realistic anyways.

I don’t know, but here’s my SWAG (scientific wild-assed guess).

Antartica is a damned big place. Nukes are little puny things. I don’t think a single “multi-megaton” device would have much of an effect for your intended purpose. You’d be better of just dropping it on your target.

You could probably back-of-the-envelope this by looking up the amount of energy released, and comparing it to the amount necessary to change some volume of ice to water. That’s assuming all the energy goes towards that purpose, which of course it won’t, but you’d get an upper bound. I bet you’ll discover that a single nuke in, on, or under antartica won’t do piddly-squat for flooding New York and California.

Ok, now I’ve gotten myself curious, so I’ll have a go at it.

I’ll go out on a limb and venture that all the world’s nukes combined would only make a very modest dent in antartica. Most nukes are in the 10’s of kilotons range. Let’s say the world has 25000 nukes with an average size of 50 kilotons, just to have some numbers to work with here.

That’s a total of about 1.2x10^6 kilotons. A kiloton is about 10^12 calories. So that’s 1.2x10^18 calories. Let’s call it just 10^18 for convenience. Let’s pick a nice round number out of thin air and say it takes 10 calories to raise a single cm^3 of antactica to melting. So we can melt 10^17 cm^3 of antactica using all the world’s nukes combined, given perfect effeciency. That’s 10^11 m^3, or about 100 cubic kilometers of ice.

100 cubic kilomters is a good sized hunk of ice, but not compared to the 30 million cubic km of ice that’s there. It would be about 0.0003 percent of antartica.

Even if my back of the envelope calcs are off by a factor of a thousand, we still only made a very modest dent.

Here’s the same sort of thing for a single weapon: the largest weapon ever detonated was about 50 Mt, which would be about 5x10^16 calories. Plugging in the numbers, we can liquify about 5 km^3 of ice with it. That isn’t very much, on a continental scale.

Nukes are puny. Just don’t get near one when it goes off, or it can ruin your day :slight_smile:


peas on earth


You could try detonating the device under the landward edge of the Ross Ice Shelf. This would dislodge a chunk of ice the size of a small country and set it adrift in the ocean. The mass of it alone should be sufficient to raise the ocean level significantly. And recent studies indicate the shelf is moving with unprecedented speed as it is.

If you’re going to detonate nuclear weopans near the poles why not do it near a volcanic area opening it up further letting the heat of the magma do the melting. As for other movies with the San Andreas idea check out View To a Kill, where the idea was to flood the Silicon Valley and corner the market on chips.

Jothar, if you wipe out New York and California, the U.S. will become Canada.

Is that REALLY what you want?

I saw a book on the shelf at the local B&N with exactly this plot. I think it was titled Icefire or something like that. Let me check real quick…

Yep. Icefire. Amazon has it at
http://www.amazon.com/exec/obidos/ASIN/067101403X/o/qid=934390731/sr=2-1/002-5904891-4903443

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bantmof: excellent reasoning. FWIW, the standard heat of fusion for water is 80 cal/gram. Antarctic glaciers are cold glaciers, meaning that they are frozen all the way to the base, thus a mean temp of -20 C is not an unreasonable assumption. Since it takes one calorie to raise the temp by 1 C, then we’re looking at 100 calories to melt a cm3 of antarctic ice. That revises the amount of ice that could ideally be melted down to 10 km3.

DIF: As the Ross shelf is already floating, dislodging it would have no effect on global sea level.

Flora: It would be worse – Canada with guns!

If you want maximum destruction with you nuke , give it a casing of Cobalt and set it off in the pacific of the coast of California The highly deadly Cobalt Isotopes will drift on the wind and kill MILLIONS. melting the ice shelf would take lots of little nukes more than one big one. A bit like taking a very powerfull hand grenade and trying to destroy a Glacier the glacier wouldn’t really notice


<insert witty sig here>

your nuke
off the coast of california

oops

It’s even worse than your calculations indicate. The heat of fusion for water is actually about 70 calories per cc, so your results are too high by a factor of seven.

Let’s be generous and say you get 14 cubic kilometers of water out of this. How much will that raise water levels?

About 71% of the Earth’s surface is ocean (according to the USGS), so that’s roughly 3.6x10^8 square kilometers. Dividing 14 cubic kilometers over that area would result in a height increase of about 0.04 mm.

Again, even if the original calculations are too low by a factor of a thousand, it only raises sea level by about an inch and a half.

The Straight Dope does not encourage or condone the use of nuclear devices in the creation of crushed/shaved/cubed/floed ice.
Neither is their use in converting water from its solid form into a gas or a liquid endorsed.

Nickrz
For The Straight Dope

God dammit, there goes my idea for serving iced drinks at the bar…


Cave Diem! Carpe Canem!

Judging by the review of Icefire, I see my idea has been done before. His idea was to use the tsunami effect to wipe out said islands. California gets wiped out (I hate the Dodgers), NY is fine, and the news crews get great footage of a tidal wave crushing Disneyland!

Jrepka: You are incorrect; the Ross Ice Shelf is not already floating – that happens to be why its called an ice shelf. If it were floating it would be the mother of all icebergs. It might be said to be partially afloat, since it is undercut on the seaward side by the ocean, but it remains attached to the continent for now. If it detached, it might generate a tidal wave, but it would definitely have a
measurable effect on the sea level.

So, sitting here, in my Northern California home…I’m just as glad it was already done in a book. Frankly, I was beginning to feel a bit like the folks in Oklahoma City…thanks for bowing to the author of “Icefire”.


Lew
“Man, the 60’s must have been real good for you!”
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“Toto, I don’t think we’re in Kansas anymore”
Dorothy…“The Wizard of Oz”

Why think small. I read if you set off two relatively small bombs (20 megaton) at the same time underwater,a mile off shore, one at Cape Cod and the other at Cape Hatteris the resulting tidal wave would wipe out the entire east coast for 10 miles inland.

JACK

I don’t know about tidal waves, but you definately have an unusual idea of “relatively small” :-). The largest weapon ever in the US inventory (back in the 60’s) was about 25 megatons, and is no longer in service. The US has only ever produced a few weapons over 10 Mt, and most of those were retired back in the 50’s or 60’s. I’m not sure about the Russians, but I’d be surprised if the US had more than a handful of >=2 Mt weapons in active inventory. The largest common US warhead is probably the B-83, with a dialable yield going up to a bit over 1 Mt. The largest one-off weapon ever detonated (by the Russians) was something around 55 Mt, IIRC. So 20 Mt is sorta pretty big, nukewise :slight_smile:

Oh - someone earlier asked about very small, tactical warheads. I found this: there was a W-51 warhead produced with a yield of 22 tons. Not kilotons, not megatons, just plain old tons. That’s still a big bang, but its only a few times more yield than a large conventional bomb like the BLU-82.


peas on earth

OK, I stand corrected. Somehow I thought there were like 100 megaton bombs.
Also it may have been 25 miles inland.
Not nice toys in any event.

JACK

I remember reading about a plan in the 60s put forward by a Pentagon think tank that proposed placing a large nuke under Cuba. Apparently Cuba is what’s known as a “pedistal” island, meaning it’s larger on it’s surface than it is at its base underwater. I guess the reasoning was that instead of repeating the brinksmanship crap over the Bay of Pigs or the missile crisis, the Pres. could just push a button and then have all the maps altered accordingly.

You could test the tidal wave procedure first off the coast of India. They would think it’s just a normal event. That many people die in bus accidents every year there.Tidal waves come around every once in a while, too. Nobody moves away from the coast.