You just gotta laugh… I noticed a story about the Westinghouse time capsule in New York from BoingBoing. So they placed a special container in 1939 50 feet into the ground in New York, and it’s supposed to be opened in 5939. The book that details the process is online and is an interesting read.
They did take quite a bit of precautions, so kudos to the people working on the project. However, this in the book caught my eye:
Another question often discussed is whether, 5,000 years from now, the coast will have sunk so far as to drown the area. Consultation with geologists and the U. S. Coast and Geodetic Survey indicate that there is probably no foundation for the common notion that the East Coast is sinking. Surveys extending over the last 40 years show that if there is any sinking at all, the rate is so slow that the change in level in 5,000 years would be only a few feet. The elevation at the site of the Time Capsule is about 20 feet above sea level.
Yes, very well. The coast isn’t sinking too fast so after 5000 years you’re still 16-17 feet above sea level, dry and clean. Excellent. Except that the current climate predictions on global warming throw a new spanner in the works: the sea level is most likely rising (see Al Gore’s entertaining TED talk on the issue). Estimates range from 0.1 meters by 2100 to 10-16 meters in just a few decades. The argumentation for the more drastic estimate is that as we know from studies of previous ice ages, when huge ice mantles start receding, there’s a very powerful current of melt water churning underneath them. And now that the polar ice caps have started to shrink, there is the distinct possibility that the currents underneath them will function as a water slide, letting a continent-sized chunk of ice drop into the sea. The north cap alone would raise sea levels by 10 meters, the western shelf of Antarctica another 6 meters, and the eastern shelf another whopping 60 meters! But of course in this case the immediate danger would come from the mega-tsunami that would most likely traverse the globe and devastate anything within some 100 kilometers from coastal sea areas. So the time capsule might need to withstand 4800 years of its 5000 year time trip in swampy ground that’s under water. Good luck with that.
Here’s images of what the coastline would look like with 17 and 170 foot sea level rises. If anyone has links to other map services or similar kind, I’d appreciate a link.
Update: Some new information on the huge lakes beneath the polar ice caps that may hasten their meltdown by some orders of magnitude.
Update 2: Nasa’s IceSat satellite has confirmed a huge subclacial network of lakes and rivers under the Antarctic. The change in the amount of water has been estimated to be as much as 2 cubic kilometers in 3 years in one lake (approximately the same amount that Los Angeles uses). And yes, the more water, the faster the ice moves towards the sea. Scientists really cannot predict what is going to happen. Ouch…