One problem you'll find is that if you're trying to create a craft to carry enough humans to restart the race, you're gonna need something in the range of 5000 breeding individuals* that aren't related to keep the genes fresh for successive generations to prevent inbreeding. And that's hoping that you don't suffer much in the way of casualties from whatever sort i.e accidents, disease, birth/newborn complications, 'artificial deaths' (such as murders) and the like.
*I can't remember where I heard this number, but I think it was a program discussing space colonies.
I had read somewhere that in our past, during an ice age, humanity went through a pinhole of 13 fertile females, we were that close :holds thumb and index finger very close together: to not being (Last caveman's last words: "missed it by that much"). I'll look for a link or something. I'll admit I may have misread, it may be that european humans went through the pinhole, or some other subset.
Broader to the thread topic:
The movie 2012 trailers seem to indicate a huge worldwide tektonic event, so even the deapest oceons would not be safe, particularly the Marianas Trench, which is a tektonic meeting point, no? The movie trailers mention the creation of a "ship" but aren't clear if it is a space vessel or an ocean vessel, but one scene shows a very strange (and big) vessel about to be clobbered by a big ship on a wave. Ooops.
Trolling aside, let's put out this scenario: The reason the Mayans ended their calander in 2012 is they saw a Meteor, perhaps a couple times, did the math, and the meteor would strike the earth in 2012. They didn't really care, it was hundreds/thousands of years away, a bronze age society, what could they do but shrug and keep doing what they do? At any rate, NASA sees the meteor out there, does the math, and it will strike the world in December 2012. Those Mayans! The meteor is big/dense enough to completely send the earth into total tektonic chaos, but probably not big enough to destroy it completely, most importantly, the biosphere. Based on archeological evidence, modeling, and some creative statistics manipulation, they determine the skies will be dark for 10ish years, there will be a resulting Ice Age, but life WILL continue. So, what do we do?
In this scenario, they key is surviving the initial event, since there will be no radiation that prevents living in the open. Being in the open ocean may be a good place to be, assuming the meteor doesn't strike in the ocean you are in. It might make sense to hang out in the center of a continent. Really, survival would be a crap shoot on the planet.
Is there time to create space arks? Are they practical? They would only be required for the actual event, people could probably return to earth in a couple weeks to a month. Caches of food would likly be required, water probably wouldn't be an issue. Unfortunately, it's the rich and powerful that would be on those arks, and are they really the "type" that could survive in a hostile natural world?
As an Average Joe... I'd probably stay somewhat put. Perhaps stock up on some food/drink/ammo. Maybe get a gun for the ammo
I can't control the catastrophe, but I'd be more worried about the people before the event, I might leave town. Without radiation, we won't have to worry much about zombies, unless the meteor has some sort of chemical, but zombies are only a problem in numbers, for a short time, so staying out of town would solve that. I wonder what post-appocolyptic society will be like. I fear the folks most prepared for it would not be folks I would want to hang with.
I'm assuming the Movie 2012 will be stupid. There look to be some cool effects, though.
