A Short Experiment:
 

Description: 2003
A coke bottle filled with water then frozen.
Motivation:
I've always wanted to do this!!!
Analysis:
We all know that glaciers are rivers of ice, this is because ice under pressure acts like a liquid.  The coke bottle is designed to hold pressure so when the water froze and tried to expand, the liquid ice oozed out the top of the bottle like playdough pushed through a spaghetti machine.  Of course once outside the bottle (there was much lower pressure) it solidified to the shape of the nozzle, a cylinder.

It is worth noting that the bottle cracked before all the water inside froze.  This is because the outside edges froze before the center.  This centimeter thick layer of forming ice had the structural strength of an arch with outward force.  An oversimplified horizontal slice is shown, the black arrows show ice expanding, the red arrows are the resulting force outward.  They are not proper vectors, I'd need a limit to do that anyway (its out of the scope of this site.  Ask me and I'll explain.)