noun
Mariana Trench
Refers to the deepest oceanic trench on Earth, located in the western Pacific Ocean near the Mariana Islands.
マリアナ海溝の最深部はチャレンジャー海淵と呼ばれている。
The deepest part of the Mariana Trench is called the Challenger Deep.
From English 'Mariana Trench', referring to the Mariana Islands. The kanji 海溝 means 'ocean trench'.