The conventional interpretation of the ice age is that there have been many ice ages. The amount of ice ages was first set to 4, but later interpretations were that there have been many more.
Another organisation, Geodoxa, presents an alternative interpretation of the data, based on flow patterns imprinted on sedementary rock. This model implies there is compelling evidence for a catastrophic end of the ice age, and there seems to be evidence only for 1 ice age.
They made a good video about some patterns that formed during the ice age, due to water flow underneath the ice:
Note: for those who wonder, Geodoxa is NOT a creationist organisation, and these scientists are NOT creationists.