Sciency Words: Chaos Terrain

Sciency Words is a special series originally created for Planet Pailly celebrating the rich and colorful world of science and science-related terminology. Today, we’re looking at the term:

Chaos Terrain

Chaos terrain is a weird concept, so I’ve decided to let a master of chaos terrain formation explain.


First, you’ll need an ocean of liquid water with a layer of water ice on top. For best results, I recommend using pure or nearly pure ice and really salty ocean water, so that they’ll have dramatically different melting/freezing points.


Next, set up some volcanoes or hydrothermal vents on your ocean floor. A little volcanic activity will cause the sporadic melting and refreezing of your ice, allowing ice water and saltwater to mix. If you do this right, you’ll end up with a salty “lake” trapped between layers of ice.


As we all know, liquid water is denser than water ice, so your lake will cause the ice above to sag and eventually cave in.


Cracks and fissures will form. Chuncks of ice will break apart, and that salty liquid water will get the chance to seep into the gaps, causing more melting and refreezing mayhem.

Finally, when your lake refreezes, it will expand (remember: ice is less dense than water) pushing all that cracked and broken material upward.


The resulting terrain will look truly bizarre—chaotic, you might say!—with huge ice blocks jutting up above an otherwise perfectly smooth landscape.


So, fellow planets and moons, what else can we do to confuse the humans? Share your ideas in the comments below!


Active Formation of “Chaos Terrain” over Shallow Subsurface Water on Europa from Nature (beware of paywall).

Europa’s Chaos Terrains from NASA Visualization Explorer.

Today’s post is part of Jupiter month for the 2015 Mission to the Solar System. Click here for more about this series.

Article by James Pailly. Check out James’ blog for more great science articles.

  • Kirov

    I’m just going to leave this here. The amount of science that goes into Elite is absolutely amazing, and this video doesn’t even touch star system generation. I honestly feel its not a video game, but a simulator with a game tacked on to it.

    • James Pailly

      That looks like some really impressive science in that game.

  • Leonardo Faria

    Now, try to imagine how the landscape could revert to smooth by means of a big ice scraper effect. You can’t use wind erosion.

    • Kirov

      You’ve got me imagining the hand of God cleaning Europa with a giant squeegee.

      • Leonardo Faria

        Oh, now I realize what all those dark streaks on Europa’s surface are. Shoddy divine de-ice cleaning.