ブレイク・マイケルのインスタグラム(blakemichael14) - 11月2日 09時27分

The phenomenon is known as differential expansion. The drink is warmer than the ice so when an ice cube is dropped in, the outer core of the ice warms up and expands while the inner core of the ice remains cold and doesn't expand resulting in the crack.
Part of the ice is trying to expand, part of the ice is trying to stay the same.

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