Website to sort and display different mountain heights?

October 30, 2009 5:56 AM

Is there a website that would show the world sorted by elevation? I recently enjoyed reading Plague Year, a post-apocalyptic thriller. The main conceit of this science-fiction novel is that a nanotechnology plague that kills any warm blooded animal (including humans), but the disease self-destructs at altitudes above 10,000 feet. How much territory would this be across the whole planet?

I liked the book. It isn't great literature, but the author, Jeff Carlson, thinks through the ramifications of a world where most mammals are now extinct and a tiny fragment of humanity clings to a few frozen mountain-tops. Carlson also doesn't shy away or sugar-coat the realities of such a situation. He also doesn't make it easy for his characters, unlike other authors in the post-apocalyptic genre. (Yes, I'm pointing at you, S.M. Stirling.) Some of the protagonists feel guilty about the cannibalism they had to resort to in order to survive, but at least they are alive, unlike 99.9% of the human race.

So, like I said, a fun read that got me thinking. My real question for the Hive Mind is-- in all the great variety of the internet, is there some sort of geographical website that would allow me to view the world through the filter of all elevations above 10,000 feet?

Which sparks another question: Have you seen the maps that occasionally appear showing what the world would look like if global warming caused the sea levels to rise 50 or 100 feet? Is there a website that will let you do that as well? Maybe even set your own parameters on how much you want the water levels to rise or fall, and then generate a map for you?

Does anyone work in the field? Isn't is called Geographical Information Systems? It sounds fascinating. I think I might enjoy working a GIS job eventually. Questions like these linger in my mind, so much so that I'm willing to spend my one-a-week currency of an AskMe question to see what the sophisticated and cosmopolitcal Mefite community has to say about it.

Thanks for your help, and I hope I'm not the only weirdo who thinks about these things!

posted by seasparrow to science & nature (7 answers total)

There are a lot of mashups out there that have Google Maps simulate flooding, and I think they have things for Google Earth too. So I'd start your search there and find one that lets you enter any altitude. I know that seems pretty obvious and I'm guessing you looked, but I know for sure I've seen this stuff before. I'll look around and post a link if I can.
posted by floam at 6:21 AM on October 30, 2009 [1 favorite]

Ok, I see why that probably won't work. Most of these are actually smarter than just showing the earth with everything above __ft blued out, they take into account where the water is already.
posted by floam at 6:24 AM on October 30, 2009 [1 favorite]

You can definitely do this sort of thing in an actual GIS program (eg ArcView), so I'd assume that you can find a way to display it in Google Earth or a similar online option.

If you have a lot of time on your hands, there are some open-source GIS programs that you could start learning with (examples), or you could see if you can come up with a sample/academic copy of ArcView to use temporarily. Once you have the elevation data, it might be as simple as just telling it to only display elevations above your cut-off line.
posted by Forktine at 6:32 AM on October 30, 2009

This page gives some pretty detailed elevation data for the whole world. However, the colorized picture is not actually particularly informative, as they were not nice enough to provide an actual key ("low" "medium" and "high" guys? Thanks for the clarification . . .).

GIS is awesome, by the way! I highly recommend it if you like maps. However, the actual jobs do often entail a lot of data management and boring upkeep, but otherwise it's pretty neat! I stumbled into the field kind of by accident, and although I'm not doing exactly what I'd like in the map-making universe right now, I am happy to be in the world of maps. They're so neat.
posted by that girl at 7:04 AM on October 30, 2009 [2 favorites]

What you want are Digital Elevation Models. You can download the US DEMs from here. I don't have time right now to find the rest of the world, and those might be a little challenging for some areas, but you could rule out entire countries by going to Wikipedia and looking up their highest point. (The highest point in Brazil is Pico de Neblina at 9820 feet.) Then you could use a GIS program to show all land masses above 10,000 ft. (Like Forktine said.)

I'd be surprised if someone hasn't done this already in some cool ajax-ified map though. If you have a Twitter account, ask the question there and tag it #geonerd.
posted by desjardins at 8:01 AM on October 30, 2009 [2 favorites]

For worldwide DEM data, get GTOPO30. There is higher resolution global DEMs out there (SRTM 90m), but for the entire world, that gets too big. Each pixel on the GTOPO30 is ~1km. Should be good enough for your purposes.

I'm going to assume that you don't have a GIS program. But, you can get GTOPO30 as .tif files. Then use Photoshop or the Gimp to create a color map that does what you need it to do.

GTOPO tifs can be found at GETech, and probably some other places.
posted by bumpkin at 10:15 AM on October 30, 2009 [2 favorites]

Back from the depths of Ask!

Here are some maps created with ArcGIS and the GTOPO30 elevation data:

*10,000 ft (KMZ)
*5,000 ft (KMZ)
*1,000 ft (KMZ)
*100 ft (KMZ)

Used Spatial Analyst's raster calculator to create the various outputs.

The idea of a website that allows for ad-hoc elevation input sounds like a great test for an ArcGIS server implementation. Unfortunately it won't be accessible to the public but I'll put your username in the comments somewhere. ^_^
posted by llin at 10:39 AM on December 28, 2009 [2 favorites]