There are many things that have to come together to create ice rings. A list follows:
Why do wings or straighter fit together, ring to ring for many rings in a family.
How
How might this happen
Big snow, deep cold snap.
thin or no congelation ice layer
Relatively few obstructions for growing families
Saturated, fresh slush is thixotrophic (think catsup). It has a tensile g of roughly 3% of frozen black ice.
