Where does “Мурманское море” come from?

Мурманское море (Russian) comes from Russian мо́ре, from Old East Slavic море, from Proto-Slavic moře, from Proto-Balto-Slavic *mári, from Proto-Indo-European móri, from Proto-Indo-European mer- — to die; to disappear; sea, lake, wetland.

Ancestry of “Мурманское море”, step by step

Мурманское море traces back through two separate lines of ancestry.

via Russian мо́ре

StepLanguageWordMeaning
1Russianмо́реsea
2Old East Slavicмореsea, lake
3Proto-Slavicmořesea; body of water
4Proto-Balto-Slavic*márisea
5Proto-Indo-Europeanmórisea; standing water
6Proto-Indo-Europeanmer-to die; to disappear; sea, lake, wetland

via Russian му́рманский

StepLanguageWordMeaning
1Russianму́рманскийMurmansk
2Russian-скийUsed to form adjectives from nouns or sometimes...
3Old East Slavic-ьскъ
Every word from Proto-Indo-European mer-Every word from Proto-Indo-European móriEvery word from Proto-Balto-Slavic *mári