In addition to the random cascade of ponds and terraces, it is sometimes possible to observe travertine domes growing when there is a slow flow of water from a spring on horizontal terrain. These structures are circularly symmetric and their shape can be compared quantitatively with predictions from our detailed mathematical theory of the growth process. In the picture below, we have compared the profile of our field observations of travertine domes with our theoretical predictions and computer simulations. The domes are formed when a very thin film of water flows, and as the dome grows, the film becomes so thin that surface tension causes it to rupture and not fully wet the surface of the dome. The result is a fluting structure visible on the lower surface of the dome.

Our theory accurately predicts the position of this wetting phenomenon in both the real world and our computer simulations.

Based on research supported by the National Science Foundation Biocomplexity in the Environment Program, through grant number NSF-EAR-02-21743.  (c) 2006.  Nigel Goldenfeld, Pak Yuen Chan, Nicholas Guttenberg and John Veysey.  All rights reserved.