The Wolf's Call

A "Wolf's Call' is a navy slang for active sonar alarm. That means the submarine is detected and targeted. Active sonars sound very different to the human ear based on the transmission frequency. Low-frequency sonars are a very deep, like a moaning bass. Medium frequency sonars are like some synth doing an imitation of whale songs. High frequency sonars are strident and creepy like "howlings."

The missile targeting France was launched from the Pacific Ocean, near Kamchatka. According to the movie, it flies above Russia, then Eastern Europe. With Earth being round, it would have most certainly flown above the North Pole.

Referenced in Notre Dame on Fire (2022)