Bubbling limits of non collapsing polarized K3 surfaces

We give an explicit and complete description of bubbling limits of a non-collapsing limit of polarized K3 surfaces in terms of the period mapping. In particular, we show that bubbling limits only depend on algebro-geometric data of the given family. As a corollary, this gives an affirmative answer to a conjecture of de Borbon–Spotti and confirms that Odaka’s algebro-geometric candidate gives genuine bubbling limits in K3 surfaces case.