Wait, I did not suggest anything, I quoted that sentence from the article which mentioned "merge". I just understood what "merge" meant, but not "steal".
I guess that explains it, thank you for responding, and sorry about the off-topic nonsense from the other user.
To maybe try and explain, as I said earlier anthropomorphization is a pretty common writing tool, which means to treat a non-person being or object as though it were a person in limited contexts. In this case the glacier is being anthropomorphized to help describe its behavior, otherwise, sure, the use of steal wouldn't really make sense.
