What role is 一面 playing in "床は一面血まみれだった"?

Question

The sentence

床は一面血まみれだった。

apparently translates to

The floor was covered with blood.

Question: What role is 一面 playing in this sentence?

It seems to me that if we omitted that word entirely, the sentence would still be translated as something like: "As for the floor, it was covered in blood". So what role is 一面 playing (grammatically, and meaning wise)?

Answer 1

It's being used adverbially, and emphasises that the whole surface was covered in blood. Perhaps you can imagine a floor which was 血まみれ ("bloodstained") but not covered from edge to edge in blood — this emphasises the completeness of the coverage, for dramatic effect.