Lex Luther vs. the San Andreas fault-line

December 7, 2005 5:23 PM

In the original 1978 Superman movie Lex Luther plans to split apart the San Andreas fault-line using Nuclear armaments - the resulting explosion destined to send the entire Californian coastline and its inhabitants to murky ocean depths.

How much explosive force would be needed to cause any such kind of earthquake? And, using the San Andreas fault as a model, could Lex Luther's diabolic plan have any degree of success?

This is a response to the increasing interest in next summer's Superman Returns epic. I hope the question sparks some interesting debate...

posted by 0bvious to science & nature (19 comments total)

This doesn't directly answer your question, but here's some good debate as related to the La Palma zone, probably as good as you'll find on the Internet regarding triggering a geological cataclysm.
posted by rolypolyman at 5:29 PM on December 7, 2005

My offhand opinion is that you would need thousands, perhaps hundreds of thousands, of nukies to move anything that big by force.

You can lube a fault line by injecting water.

Re; dumping Calif. into the ocean, it won't work. The pacific plate is headed north, the one Cal. is mostly on is headed south. You might nudge them a little, especially if they were ready to move anyhow, but no way are you going to make them turn.
posted by Ken McE at 5:35 PM on December 7, 2005

Oh man I'm googling furiously, I found a debate just about this. The probability that a terrorist attack would ignite the super-volcano or some similar untapped natural disaster. I'll try to get you a link but the energy required is several magnitudes greater then the amount of nuclear material available in the earth's crust. This was more directly in regard to the so-called supervolcano in Yellowstone.

I think the conclusion was that we simply don't know how much energy is required, but it would require the resources of an entire nation or multiple nations to make it happen.
posted by geoff. at 5:49 PM on December 7, 2005

You might find this interesting: A nuclear bomb exploded by the soviets generated over 1% of the power output of the sun over a short period. I think it's reasonable that if you stacked a few of them in the fault it would do something. Especially considering 100 of such bombs would be able to generate a greater power output THAN THE FREAKING SUN..... umm, sorry, I get a bit edgy around explosives.
posted by blue_beetle at 6:26 PM on December 7, 2005

honestly, no amount of explosive is going to cause an earthquake big enough to do what you're saying.

an earthquake is a strain-relieving event. as tectonic plates move past one another, the upper layers of the crust stick together until enough tension is built up that something snaps and they slide wildly past each other, releasing all that stored energy and finally settling down into a new equilibrium. the key to thinking about this is to realize that on the energy scale considered, the surface of the earth is not hard and brittle like our everyday experience with rocks tells us, but rather soft and subject to plastic and elastic deformations.

anyway, this strain-release process repeats over and over, and is an example of what physicists and engineers call stick-slip motion. it's just like when you slide a chair across the floor and someone thinks you farted - the chair's legs stick to the floor, then release, over and over at a frequency (that curiously matches the resonant frequency of the human buttocks- hmm). in the case of earthquakes, this simply happens on an enormously long time scale, tens to hundreds of years between slips.

the point of all that is to illustrate that, if one were to use a suitable explosive to set off the slip event, the amount of energy that is released in the resulting earthquake totally unrelated to the explosives, and is only the stored energy in the fault itself, which would be released during a natural earthquake a few years/decades/centuries down the line. in fact, given that you're setting it off prematurely, i think it would probably be a lower magnitude than the earthquakes we see naturally.

as for sinking california into the ocean - the land would only "sink" if the land underneath it were to be physically displaced. i don't think you could do this with explosives without vaporizing whatever surface was above it, and at that point you'd simply be blowing a humongous hole out of the west coast.

this is theoretically feasible, so here's a back of the envelope calculation to get us in the ballpark:

i will make some ridiculous simplifications - one, i will treat "california" as a 200 mile x 800 mile slab that is 2 miles thick (reasonable for putting the whole thing underwater, i guess). if you treat the entire state as made of silica, which is the major component of the earth's crust, then california has a molar mass of 60 g/mol, a density of 2.6 g/cm^3, and therefore is:

200 mi * 800 mi * 2 mi * (1.6e5 cm/mi)^3 *2.6 g/cm^3 * 1 g/60 mol = 5e19 mol of silica.

silica is made of silicon-oxygen bonds, and it may be overkill to treat it this way, but another ridiculous simplification will be to say that "blow up" means "break all the bonds". the bond energy of Si-O is 450 kJ/mol, so we get 2e22 kJ = 2e25 J required.

the energy released by the most powerful hydrogen bomb ever exploded was 250,000 terajoules - tera means 1e12, so this is 2.5e17 joules.

in other words, we'd need around 10 million of the most powerful thermonuclear weapons ever built in order to vaporize california. due to my gross oversimplifications, this is probably only correct within an order of magnitude or two, but either way it's a tall order.
posted by sergeant sandwich at 6:38 PM on December 7, 2005 [1 favorite]

Damn! I was all excited that I could actually put my hard-earned (and expensive) B.S. in Geology to use, but sergeant sandwich beat me to it.

There are some places in the world where the earth's surface is sinking (one plate sliding under another) but California isn't one of them.
posted by luneray at 6:58 PM on December 7, 2005

what if Lex and Superman switched places, and Superman was evilly trying to sink california into the sea? could he do it? would he have to use nuclear devices?
posted by carsonb at 7:22 PM on December 7, 2005

dude, superman can do anything!
posted by sergeant sandwich at 7:26 PM on December 7, 2005

The U.S. has investigated the idea of using nuclear explosions for earth-moving in Operation Plowshare.

Scrapped due to the observation that if you wanted to use whatever you had just built with nukes, you needed a lead-lined suit.
posted by jellicle at 7:40 PM on December 7, 2005

Great stuff Sergeant Sandwich...

So its not a viable way to start earthquakes, but what about subsiding them? If what you say is true then the detonation of enough bombs around (or under the ground of) a fault line could help release the pressure build up associated with plate slippage. Maybe in areas such as the San Andreas fault this method could be used to buy time before the next 'biggie' occurs. What do you think?
posted by 0bvious at 8:00 PM on December 7, 2005

Also, California won't sink because it isn't floating. It's attached to the ocean floor!
posted by Hildago at 8:10 PM on December 7, 2005

obvious:

here are some references to the sort of fluid injection schemes that Ken McE posted about above. i've never heard of explosives being used, but the idea is reasonable enough. i would think the big problem with it is figuring out where the stress points are along the fault. it may not be this simple. i have a picture in my head of the entire continent being hung up on some little piece of rock that juts out; really it's probably far more complicated with distributed shear forces and soft, semi-molten interfaces.

there is also the technological problem of drilling deep enough to do anything where it matters - earthquake epicenters are often 10-20 miles below the surface; the deepest hole ever drilled by people is only 12 km.
posted by sergeant sandwich at 8:35 PM on December 7, 2005

scientists gettin up close and personal with the san an fault line
check story here...
posted by 0bvious at 11:56 PM on December 7, 2005

Apophis comes to mind...
posted by mhuckaba at 12:14 AM on December 8, 2005

ss's calculations are to vaporize califronia. turn it into gas. not start an eartquake. the two are completely unconnected. after ss has finished, there'd be no california left to shake, just a big ball of gas.
posted by andrew cooke at 4:38 AM on December 8, 2005

If this story has any validity whatsoever, then it seems even really tall buildings can put enough stress on the ground beneath to have an effect on seismic activity. If that's true, then it seems unquestionable that a nuclear bomb could stir some shit up.
posted by louigi at 10:26 AM on December 8, 2005

A nuclear bomb exploded by the soviets generated over 1% of the power output of the sun over a short period.

"A short period" here meaning "an almost unimaginably short period," i.e. 39 nanoseconds. That's 0.000000039 seconds.

Especially considering 100 of such bombs would be able to generate a greater power output THAN THE FREAKING SUN.....

...for 39 nanoseconds. On the other hand, it would take 2.5 billion of these bombs to produce as much energy as the sun does in one second. So no need to get too edgy just yet.
posted by DevilsAdvocate at 11:54 AM on December 8, 2005

And if all this is true, would somebody like to buy the vacant lot I bought on the landward side of the San Andreas fault? I was hoping for a beach house after the big one, but that might not work out.
posted by donfactor at 12:31 PM on December 8, 2005

A nuclear bomb exploded by the soviets generated over 1% of the power output of the sun over a short period.

it is, perhaps, a sad commentary on human nature that what is probably the loudest signal ever sent to the universe that could communicate "we are here!" to those beyond the stars was the detonation of a weapon designed to slaughter millions in one stroke.

i'd stay the fuck away, too.
posted by sergeant sandwich at 10:15 PM on December 8, 2005