"rippling"
If it is then its caused by the backing expanding when it becomes damp, it will go back when it is dry be careful not to place heavy items on the carpet which may prevent it returning to normal.
I have had two carpets ripple it can be scary but took advice on here and they were right it did go back, what i do now is warn customer of this possibility prior to cleaning sculptured carpets can be prone to it, but its the backing expanding.