The story
From being chosen in a competition held among students in the Marianas to name the deep by the discovery team. From association with mythological sirens of the deep.
Etymology from Wiktionary, CC BY-SA 4.0.
Sirena Deep
Today it means: A deep in Mariana Trench, Pacific Ocean; the third deepest known place on Earth, second deepest in the Mariana Trench. Full definition →