[Sooth2222]

Olsen claims that glacier ice has a better taste and, because it has been compressed for centuries, thaws more slowly than regular ice cubes.

When did the NEA take over Norway's schools?

[Fzob]

thaws more slowly than regular ice cubes.

There may be some truth to this. Glacier ice is typically compressed snow with a certain amount of air. So it has a lower density that "regular" ice. The presence of air bubbles could certainly slow heat transfer and make the ice thaw more slowly. The part that is not mentioned is that if there is lower density due to trapped air there is also less btus to transfer to the drink.