Deep

Definitions: (1) possessing a penetrating intellect; wise; sagacious; (2) characterized by profundity of feeling; intense; (3) engrossed; involved

Quotes:
• Details matter. They create depth, and depth creates authenticity. — Neil Blumenthal (? 1980-) American entrepreneur
• It always comes back to the same thing: go deep enough and there is a bedrock of truth. — May Sarton (1912-1995) American Poet

Observation: The Mariana Trench is an oceanic trench located in the western Pacific Ocean, about 124 miles east of the Mariana Islands; it is the deepest oceanic trench on Earth. It is crescent-shaped and measures 1,580 miles in length and 43 miles in width. The maximum known depth is 36,037 feet; 6.825 miles at the southern end of a small slot-shaped valley in its floor known as the Challenger Deep. If Mount Everest were placed into the trench at this point, its peak would still be underwater by more than 1.2 miles.

Symbol: the abyss