Breakdown of Es ist umso unheimlicher in dieser Tiefe, als man außer dem Wasser nichts sieht.
sein
to be
es
it
in
in
das Wasser
the water
Questions & Answers about Es ist umso unheimlicher in dieser Tiefe, als man außer dem Wasser nichts sieht.
How does the umso ... als structure work in this sentence?
The phrase umso combined with a comparative adjective and als translates to "all the more [comparative] ... because/since ...". Here, umso unheimlicher sets up the idea that it is "all the more eerie", and als acts as a causal conjunction explaining the reason why.
Wait, doesn't als usually mean "when" or "than"?
Yes, but in this specific umso ... als structure, als takes on a causal meaning similar to weil or da (because/since). It introduces the reason for the statement in the first half of the sentence.
Why is the verb sieht at the very end of the sentence?
Because als functions as a subordinating conjunction here, it creates a subordinate clause. Just like with weil or dass, this kicks the conjugated verb (sieht) to the very end of that clause.
Why is it in dieser Tiefe rather than in diese Tiefe?
The preposition in is a two-way preposition. Since the sentence describes a static state or location (being at this depth) rather than a movement into a new location, it requires the dative case. Tiefe is feminine, so the demonstrative pronoun becomes dieser.