Vertical sinusoidal forcing of glycerin-water establishes periodic surface waves. With increased forcing, the solution reaches a quasi-periodic state of various wave heights. Under even higher amplitude, jets can be produced. These jets are examples of singularities, defined by a diverging velocity gradient. Difficulties in modeling the surface arise from nonlinear boundary condition equations.

Read a Letter to Nature: "Singularity dynamics in curvature collapse and jet eruption on a fluid surface"
http://www.nature.com/nature/journal/v403/n6768/full/4034...

Visit the Lab:
http://complex.umd.edu/ (less info)