A remake of an animation NASA made back in 2008, but at high resolution and with edited timing (https://svs.gsfc.nasa.gov/3487), the previous version was 1024×512 while this one is 3840×2160 (4K).
Three-fifths of the Earth’s surface is under the ocean, and the ocean floor is as rich in detail as the land surface with which we are familiar. This animation simulates a drop in sea level that gradually reveals this detail. As the sea level drops, the continental shelves appear immediately. They are mostly visible by a depth of 140 meters, except for the Arctic and Antarctic regions, where the shelves are deeper. The mid-ocean ridges start to appear at a depth of 2000 to 3000 meters. By 6000 meters, most of the ocean is drained except for the deep ocean trenches, the deepest of which is the Marianas Trench at a depth of 10,911 meters.